Isabella's Dark Side

Note: I do not own Phineas and Ferb nor any characters mentioned in this story. Non-Canon and for entertainment only.

Content Warning: Many lemon scenes, as well as orgies and pregnancy/impregnation/harem.

-Isabella and Phineas are around their mid-20's, living together in an amazing house large enough for Phineas' tinkering and Isabella's many hobbies as well. All of the Fireside girls are around the same age, but Isabella is the only Fireside girl to have kept an ongoing relationship with anyone for more than a few months.

Enjoy!

Chapter 1: The Gathering and Revelation

It's around seven at night as Isabella Garcia Shapiro resides to her bedroom after making herself a small meal and working on grading her students' math papers. Another lonely night without Phineas awaits her. Isabella has always been known for helping others, but she never takes the time to take care of herself when it comes to her needs. Dating Phineas for all these years is something she would never want to lose, but with Phineas being gone due to all the traveling he does for his own company to work on projects and close business deals, she misses the companionship with her boyfriend. Phineas would come home after weeks of traveling and rarely took any vacation time to spend with Isabella, and Isabella's own job of teaching private school kids drains her energy as much as Phineas' job does, leaving both of them too tired to spend some true alone time together. Having to deal with teenagers that can't do basic math and coping with their attitudes towards her when she tries to help doesn't make things easy either. When she does return home to an empty house, Isabella is relieved to have some alone time but craves the passion that she and Phineas used to share in their college life.

As time grew on, Isabella decided to take matters into her own hands and acquire certain items to help her cope. She was always loyal to Phineas and would spend her entire life with him, but in the times she's alone, while her devotion to Phineas may cope, her urges cannot. Both Isabella and Phineas made enough money to afford a large, comfortable lifestyle, and with Phineas still somewhat naïve, Isabella was able to amass quite a large collection of toys for her pleasure without him knowing. Tonight was one of those nights to where she would use them.

Isabella goes into her walk-in closet with her most treasured clothes including her old Fireside Girl's uniform, and then one tailor-made for her when she was older that she received as a gift from her friends as a gift from when she went away to college with Phineas. Amongst the clothes are also everything that Phineas has gotten her as a gift for anniversaries and birthdays, but her most prized possessions lay under her shoes.

She takes a key hidden in her Fireside Girl outfit and unlocks a hidden compartment after moving her shoes out of the way from the rest of the floor. Unlocking the compartment, it rises up to reveal a mass of sex toys, vibrators, whips, chains, handcuffs, and many more items that she enjoyed. All these items were colored differently, but one stood out from the rest. A perfect replica of Phineas' penis, molded out of orange plastic and sitting on the highest shelf. She smiles weakly, wishing her boyfriend was here with her. In the middle of the compartment lies a full dominatrix outfit with stockings, lace, and nipple clamps. Notorious for her plan making, she strips down in her closet, takes the entire outfit as well as several vibrators and dildos, and lays them out on the bed, smiling at her imminent self-pleasure.

However, as she looks at her toys, she desires something more personal, more friendly, and also kinkier. She looks back into her closet and sees her Fireside Girl uniforms.

All of the Fireside Girls keep in touch through email and other social media, but they also keep a group chat that they chat in whenever they can. It was a Friday night, and she knew that her friends would come to her aid whenever she needed it. The girls were no stranger to each other's wants and desires, seeing as how Isabella corroborated her troops' activates around Phineas every summer. Summer activities of Phineas' were always requiring changing clothes for different tasks and the girls had grown accustomed to seeing each other naked or changing. They never saw it as awkward, but more of a bonding moment. That being said, Isabella grabs her phone and punches in her message to the group.

"Girls, emergency Fireside Girls alumni meeting, my house, 1 hour. Bring some booze, wear something comfortable and keep an open mind."

She looks at the message hesitantly, holding her finger over the send button. She thinks to herself, "Am I willing to throw away my friendships with my best friends if they say no to this?" Her fear of denial and loss suddenly takes hold of her. "What if my friends think this is weird? What if they don't feel the same way?" She takes a deep breath and pushes send. They would never turn their back on Isabella, as she had never done to them.

"The worst thing to happen is they say no."

Five minutes go by and no response. Ten minutes go by and no response. Isabella feels a tear to her cheek, and as she starts to put everything away, her doorbell rings. She smiles and puts on a nightgown and a pair of socks and goes to the door. She looks through the peephole to find Gretchen, Ginger, Katie, Milly, Holly, and Adyson all smiling with booze and a handbag apiece. She throws open the door and gives the group a huge hug.

"Thank you so much for coming you guys, you're the best!" she says with a huge smile on her face.

"You're our leader Isabella, we'd do anything for you," said Gretchen, with everyone smiling and nodding in agreement.

Katie smiles "We all brought something different for a drink, so let's get this meeting started!"

Isabella invites them in, bringing them down to the den that Phineas and Isabella designed together to accommodate as many people as possible. She brings out wine glasses, ice, and snacks.

Isabella pours everyone a drink, starting the meeting.

"I appreciate everyone coming to this emergency meeting on such short notice, but the six of you are my closest friends and I know you'd come. This meeting is about the most important thing we as women want."

The girls ponder what this is and look at their former leader, confused but intrigued. Adyson speaks up.

"Does this have to do with you and Phineas?"

Isabella nods and the girls smile. "What's going on now Isabella?" Katie says, wanting to learn more. The girls knew everything Isabella loves about Phineas and how she's so madly in love with him, but they seldom thought of the times where Phineas did something wrong.

"Is he hurting you?" says Katie. "Cheating on you?" says Holly. "Has he lost his love for you?" says Gretchen

Isabella finishes her wine and starts to pour another glass, trying to figure out how to tell her friends her troubles.

"No, not at all! He hasn't done me any physical harm and he's not cheating on me! It has to do with him not being around very often, and um…." she starts to fade out the answer in embarrassment.

Ginger sits closer to Isabella and wraps an arm around her shoulder. "Isabella, you can tell us anything."

Isabella asks everyone to close their eyes as she does something. Isabella leans forwards and kisses Ginger on the lips, sliding her tongue into Ginger's mouth and moaning. Ginger doesn't move out of shock, but to soak in what's happening. After a few seconds, Isabella leans back. Afterward, she goes around and does the same to each of the girls, kissing them with the same level of passion and desire. Ginger, a little embarrassed and mainly confused, starts her onslaught of questions.

"Isabella, why did you kiss us? What does this have to do with Phineas? Why would you do this?"

Isabella comes out and addresses the group.

"You guys are my best friends, and I love you all as friends, but with Phineas not around very often, I feel as if I've lost my true love. I started thinking about how we've all known each other for our entire lives, and I just wanted to see if you guys felt the same. I've been wanting Phineas for the last two weeks and he hasn't been home at all. We talk and Skype all the time, but it's not the same. I just wanted to feel like someone genuinely cared about me as I care about Phineas, but something different. I'm sorry if this is sudden, and to be blunt, I need to get laid and you guys were the closest people besides Phineas that I have. I love all of you just as much as I love Phineas."

After her large confession, she sits back down and sighs, finishing her second glass of wine. The girls look at each other and at Isabella, thinking of their emotions and what they just felt. They always thought Isabella would have eyes for only Phineas, but the fact that she had wanted to be with all of them brought a special warmth to not only their hearts but to their bodies as well. It's as if something snapped and the girls all decided to want what Isabella wanted. They knew Phineas loved her with all his heart, but to see him somewhat neglect her was a saddening thought as well.

Ginger is the first to act, and stands up and smiles, with a few tears running down her eyes.

"Isabella, if only you brought this to our attention sooner. I think it's safe to say we've all had this same thought now and again. Seeing you and Phineas as the only couple kind of had the same effect. I've been wanting to get together with someone but never had the confidence to do anything about it, and I think everyone has the same feeling. Seeing each other grow up and grow more attractive is something I can barely stop thinking of."

The girls all nod in agreement, each wanting more of Isabella and each other.

Isabella smiles and hugs everyone again. "Thank you so much, you guys."

Adyson smiles and starts stripping her top and skirt off. "So are we going to just sit here and hug or are we gonna fuck?"

Everyone smiles and starts stripping. Everyone tries to be as seductive as they can as they strip down to their bras and panties. Ginger rocking a cute white bra that holds her DD-Cup chest and matching lace thong. Gretchen wearing baby blue lingerie with her B-Cups, Katie and Milly are coincidentally wearing matching pink boy-shorts and bras, Adyson wearing no bra showing off her D cups but a rather raunchy red frilly thong, and Holly wearing a small pink bra for her B-Cups and a frilly g-string.

Everyone looked at Isabella who took off her robe and revealed her curvy hips and DD-cups with a thong to match her robe. She smiles and brings her new lovers upstairs to her room with her giant bed.

"Before we begin, I think we might need a few things," Isabella says, bringing out all of the toys she had kept hidden out to her friends to gawk and admire. Everyone grabbed a toy and got onto the bed, finding themselves a partner or two as they removed what little clothing each of them had on.

Isabella decided to continue what she started with Ginger, cuddling her face in her hand while kissing her lips slowly, rubbing her other hand along Ginger's chest. Ginger moaned into the kiss, sliding her tongue into Isabella's slowly and fighting for dominance. Ginger had the advantage of being on top, but Isabella was not backing down as she slid her hand to Ginger's ass and spanked it hard.

Ginger cries out in ecstasy as Isabella spanks her more and more, sliding Ginger's dark brown nipple into her mouth, savoring her newest lover's taste.

Adyson, Milly, and Holly decided to form a triangle, each of them eating out another while using a vibrator on their own clits. Adyson took Milly's soft, puffy pussy into her mouth and sucked slowly, making Milly squirm as Milly slid her tongue across Holly's outer-most walls. Holly gasped, closing her legs as she focuses on Adyson's ass, sliding a finger in her butt and nibbling on her clit. As the girls move more and more, their motions become more in sync and they constantly switch back and forth from pleasing their designated partners' ass or pussy.

Gretchen and Katie find themselves at the foot of the bed, making out as they grind their shaven pussies against each other, fighting over dominance of the vibrator rubbing their clits. Katie smiles as she breaks the kiss and nibbles on Gretchen's earlobe, making her moan louder as Katie's tongue licks around her ear as well. Gretchen smiles and giggles at the tickling sensation as her pussy gets wetter and wetter. As the couple continues, Isabella looks around and smiles at everyone enjoying themselves. With a sense of confidence, she reaches to her nightstand to get a large 8-inch strap-on with a small tube of lubricant. She smiles and stands up, putting the strap-on around her waist, attaching a small vibrator on the inside where it presses against her clit.

As Isabella prepares herself, Ginger quickly gets the girls lined up with their asses up and pussies spread, waiting to be pleasured by their leader. Each of the girls smiles back and in unison, seductively chant out "We're ready Mistress Isabella". Isabella blushes and smiles.

"You guys don't have to call me Mistress, but if you all act this naughty I guess you must be punished"

Isabella moves in front of each girl and quickly licks each of their pussies, savoring the unique tastes that each girl possesses. She turns her vibrator on and positions herself behind Ginger, the eager girl moaning as she feels Isabella move into her slowly. Ginger hadn't felt this much pleasure in so long, and she yearned for more, crossing her legs so that her pussy tightens. While Ginger is pleased, each of the other girls takes a partner to continue making out and feeling around for each girl's specific turn-ons.

Making sure to not leave anyone out, Isabella only spends a few minutes with each girl before moving on. She pulls out of Ginger quickly and licks her pussy another time, sensing how much it is throbbing after she pleasured her.

Pleased by her work, she moves on to Milly. Milly's nerves start to set in as she pushes away from Isabella as Isabella attempts to slide into her.

Isabella rubs Milly's pussy as she climbs up to the bed and kisses her surprisingly.

"Milly, don't be nervous, I won't hurt you," Isabella says reassuringly, smiling and seeing a feign smile from Milly.

"I know you won't Isabella, I'm just nervous and excited at the same time,"

Isabella rubs all along Milly's body, making Milly whimper and squeal in delight. Aligning her strap-on with Milly's pussy, she moves in slowly, massaging Milly's clit slowly as she moves in. Milly feels a bit of pressure as her mistress makes them one, and once Isabella is fully inside, Milly lets out a sigh of relief and pleasure. Isabella thrusts in and out slowly, spanking Milly as Milly moves more and more against Isabella's amazing cock. Milly's arms give out from the pleasure and her ass moves higher in the air. Isabella climbs up on the bed and pounds Milly's pussy harder and harder as she feels Milly tighten up and her squeals turn into loud moans as she begins to cum. Isabella leans forward as Milly squirts all over Isabella as Isabella pulls out and slides her tongue deep into Milly's pussy. Isabella notices how bitter she tastes, but moans as Milly squirts more and more onto her face. Milly slumps forward and moans as she recovers.

"Two down, four to go," Isabella smiles and moves on to Gretchen.

Gretchen's playing with her pussy as she awaits her turn, but also slides a finger into her ass as she's gotten so wet and had never tried anything there before. Noticing this, Isabella pushes Gretchen down and mounts her ass, smiling as she rubs her tip all over Gretchen.

"I see Gretchen has about as much of a kinky side as I do," Isabella says slyly. She spanks Gretchen and Gretchen moans out "Please Mistress please put it in I need it so bad."

Isabella had tried anal before with Phineas but never got to see what it's like being the one giving anal. She smiles as she pushes deep into Gretchen's waiting ass, admiring how tight it is. Gretchen moans in pleasure and a small bit of pain, fingering her pussy as she takes inch after inch of Isabella's strap-on into her. Gretchen moans out Isabella's name over and over again, and Isabella grabs her chest and pinches her nipples, making Gretchen squirm more. Out of nowhere, Isabella pulls out and switches to Gretchen's pussy, humping away as she sees Gretchen's eyes roll back with ecstasy. Gretchen moans more and more, squirting all over the place uncontrollably and Isabella, like the other girls, buries her face savoring Gretchen's juices. She notices she tastes sweet and tangy, licking her lips and dives into her ass as well, something she'd never tried. She admired this new delicacy and retreated for now, as there were more women to please.

Holly was the next to be pleased. She smiled as she raised her butt high for her mistress, waiting to satisfy her. Isabella was known to be strong, so she decided that after sliding into Holly's shaven puffy pussy that she would lift her up and fuck her deep and hard as Holly's pussy fell onto her strap-on, making Holly beg for more. Holly moved her hand down to feel the strapon bulge in her stomach, rubbing her clit as she sees how much she can take. Isabella kisses her neck as she thrusts in and out, she then lays back down and continues her treatment of Holly. As Holly moans out, Isabella commands Gretchen to sit on her face as she'd seen her recover. As Gretchen begins to climax, she motions for Adyson and Katie to come over and prepare themselves. Isabella had grown tired with so many lovers and decided to have the two remaining girls service themselves upon her. She thrusts once more into Holly, sending the young, beautiful ebony goddess over the edge and squirting all over the girls. She had the most potential when it came to squirting it seemed. Katie and Adyson took their positions upon Isabella, Katie on her face and Adyson riding Isabella. Gretchen takes Holly and holds her in a warm embrace, kissing her slowly and rubbing her body passionately.

Katie and Adyson waste no time in servicing Isabella. Katie rides on Isabella's face with an ever-growing passion, leaning forward to indulge Adyson in a lover's kiss. Adyson enjoys the kiss as she continues to ride Isabella, sliding her hand to her clit as she rides her new lover. Gretchen comes from behind and slides a welcome dildo into Adyson's waiting ass as she works on suckling on Adyson's gorgeous breasts. After a while, Isabella feels that someone had turned up the vibrations of her toy and added another one to her own ass. It was Milly, coming over once again as she suckles on Isabella's chest as well. Gretchen and Holly come together and pleasure members as they pleasured them, completing the group enjoying each other at the same time. They could all feel each other's climax about to happen. Isabella quickly gets up and positions herself in the center, with the other women's pussies spread around her. She fingers and rubs every part of their pussies as fast as they can, and as she herself begins to climax, she is showered in a fountain of her friend's love juices.

The women all fall back onto the bed and catch their breaths, moaning and feeling the after-effects of their new bonding. Isabella sits up and walks back to the den to grab the wine and water for her friends. Each girl gladly takes a glass as they reconvene to talk about what just happened.

"I'm so glad everyone had a good time and was able to unwind a little today," Isabella said, sipping her wine slowly. "I wanted to make sure everyone got enough attention."

The group smiles and nods.

Gretchen stands up quickly but slides down realizing Isabella's work on her had left her extremely tired. "I would say that we could say the same to you. I haven't done anything like this with anyone since freshman year of college, and I have to say, boys have no idea how to please a woman."

Everyone smiles and giggles, thinking about Gretchen's comment.

"So Isabella, when you and Phineas do make love, is it as passionate as what you just experienced?" asks Milly. The girls look on with curiosity at their friend. Isabella blushes a bit and responds simply with "He's bigger than the toy I used tonight." The girls all squeal as they get excited about the thought of Phineas's massive cock. "Have you thought about kids yet Isabella?" says Milly, rubbing Adyson's shoulders as she is starting to get horny again.

Isabella shakes her head. "He's so busy that we haven't really talked about it. We've got enough money to last us a long time due to his inventing, but I'm not sure he wants to settle down yet." Milly slides over and comforts Isabella. "Well, you'd sure look amazingly sexy while pregnant." she smiles as she plants a quick kiss on Isabella.

Isabella hugs her and takes another sip of wine. "Have you girls thought about having kids yet?" The girls shake their heads. "When we all find a man who can fuck us as you can we will," says Gretchen. The girls all laugh and drink more and more. Isabella's brain just came up with an amazing idea that would both bring Phineas closer to her as well as her friends on a much deeper level.

"Girls, what if Phineas got us all pregnant? He's always been a family man with his family, so if he had a family of his own then maybe he'd settle down."

The laughter turns to silence as they all contemplate being pregnant with Phineas' child. Adyson speaks up, "Isabella I think you've had too much to drink." Isabella shakes her head and stands up. "Ladies, you know how much I love you guys and how much I love Phineas. I wouldn't want to spend my life with anyone else other than you six and him. Growing up I noticed that you all seemed to flirt with him, but out of respect for me, you left those feelings aside so I would be happy with him. Now I'm happy with you guys as lovers and friends, and I want to share him with you all. "

The group takes in what their friend says and Holly is the first to stand up.

"I'm in if it means spending the rest of my life together with you Isabella." she smiles as she gives Isabella a hug. Gretchen and Milly do the same and agree to what Isabella has to offer. Adyson, Ginger, and Katie all stagger for a second, realizing the scope of what Isabella wants to do. Ginger always thought of settling down with her own man and family, Adyson wanted to be her own boss and continue building her company, and Katie was never known for anything so out of the ordinary before tonight.

Ginger speaks up "Isabella, I think we should continue to talk this through. You and Phineas have something special together and we don't want to get in between you and him. It took him years to realize he loves you and wants you, but I think he's spending so much time away from you to be able to provide for the family that he eventually wants to have." Isabella contemplates her words and prepares to dispute her ideas.

"Ginger, you're one of my best friends and after tonight, I want you more than I've ever wanted anything. I want you all in the same way. To share a bed with all of you, make new lasting memories, explore new avenues of pleasure and pain with you, all the while growing our relationship to a level no other group could comprehend. I'm willing to share the man I love with the women I love."

After hearing Isabella's passionate words, Ginger steps forward and smooches Isabella with tears of joy in her eyes. Adyson and Katie do the same and the girls come together to embrace their new companionship as a family.

"Alright girls, now the next thing to do is figure out how to get Phineas into completing this new group of ours," said Isabella, rubbing her pussy anticipating all the love making her new family was going to create. "Isabella, he'll do anything for you. Let's get him home soon," said Gretchen, licking her lips as she sees Isabella playing with herself.

The girls all say "agreed" before begin again as the girls start their second round of love-making.