Stiles could feel his heart beating rapidly. He was so nervous. He was starting to get annoyed that he had sobered up enough on the ride back to the McHale's place.

He didn't know if this was a very good idea after all. What if Derek didn't like this little surprise he planned? God, this was so cliché. A fireman costume? Really? This was probably the most used outfit in all of porn industry. He should have thought of something more original… No, this is not the time for second guesses. This was all he had prepared. Stiles curses himself for not having a plan B. Oh well, it was now or never.

"Trick or treat." Stiles walks out of the bathroom and smirks at Derek who was now only wearing boxer-briefs and a wife-beater.

Derek turns around and when he sees Stiles in his costume he can't help but chuckle.

Stiles' ears start to burn, his whole face is heating up and it turns bright red. He lowers his head, trying to hide his utter embarrassment.

"I knew this was a stupid idea." Stiles mumbles.

"No. No. I'm sorry." Derek apologizes, still grinning. "You look adorable."

"I'm not supposed to look adorable. This is supposed to be… um…sexy." Stiles' voice is barely audible at the last word.

Derek looks at him, smiling. "Come here." he says, reaching out for his boyfriend.

Stiles starts to slowly make his way towards Derek, keeping his eye on the floor, clearly too embarrassed to look at Derek.

When Stiles is close enough, Derek grabs him and pulls him in into his lap.

"You are sexy." he whispers into Stiles' ear, pulling his boyfriend even closer to him.

"You're just saying that because you feel bad for having laughed." Stiles mutters.

"I mean it." Derek reassures him. "You need to learn how to take a compliment."

Derek's face is now nuzzled in Stiles' neck, he breathes in on the teenager's skin, letting out a warm breath that makes Stiles shiver. Derek starts to lick and nip, knowing that he is leaving a bruise on Stiles' neck. He loved doing this, loved marking Stiles to let everyone know that he was his. He stops licking and grins when he hears his boyfriend let out a little whimper.

Derek grabs Stiles, throws him in bed and leans on top of him. He starts kissing his neck and makes his way up until he reaches his ears, then he slowly begins nibbling on them.

"Do you really think I'm sexy?" Stiles suddenly asks sheepishly.

Derek pulls himself up, so he is looking directly into his boyfriend's eyes.

Stiles could be so insecure sometimes, it made him sad to think that his boyfriend didn't realize and couldn't see how amazing he really was.

Derek smiles. "Yes." he says sincerely. He lowers himself so that he can kiss Stiles.

Stiles moans are muffled by their kiss. Derek's familiar warm breathe inside his mouth making him forget all about his embarrassment.

Derek slowly starts trailing kisses down Stiles' body.

"You" he kisses Stiles' collarbone.

"Are" he kisses Stiles' nipple.

"Perfect" he kisses Stiles' abs.

Derek is now face to face with his boyfriend's growing bulge.

"Looks like someone's happy." he says, smiling, as he pulls down Stiles' red underwear and lightly pats the erect penis in front of him.

His smile gets even wider as he hears Stiles moan in pleasure.

Derek stops teasing and takes Stiles in his mouth, licking the base of the teen's cock before putting it all in.

Stiles' moans starts getting louder and his grasp on the bed sheets tighter. "Ahh. Derek."

Derek starts to move his tongue around, gently licking, before he gets into a steady pace. Stiles' toes curled, his tight grip now on Derek's hair, pulling him closer. He lets out a needy moan.

"Derek, I- I'm about to-"

Derek abruptly stopped sucking. He got up to meet Stiles' eyes. "I don't want you to cum just yet." he smiled.

"I want to be inside you when you cum. I want us to cum together." Derek whispered softly. "Would you like that?"

"Yea… Derek, I want you inside me. Fuck, I need to feel you inside me." Stiles said with a voice filled with lustful hunger.

Derek easily turned Stiles so that he was on his back. He reached out for the drawer next to his bed, took out a condom, opening the package with his teeth, lowered his underwear and rolled down the rubber until the base of his dick. He spreads Stiles' legs, spits into his hole to lubricate it, and starts teasing by rubbing his dick in the little crack above his butt.

"Derek… please." Stiles groans.

Derek can't contain himself much longer. He leans on top of Stiles, wrapping his arms around the boy, as he slowly starts sliding his dick inside him.

Stiles lets out a moan that he muffles by burying his face into a pillow. Derek starts thrusting at an increasing speed, turned on by the noise his boyfriend is making.

"Fuck Stiles, you feel so good." Derek is panting. "Do you like this? Do you like to feel me inside of you?"

Stiles turns his head to the side. "Ahh… Derek… It feels so good. Ahhhh." he moans, tightly clenching the sheets.

Derek nuzzles into Stiles' neck, kissing it. "Stiles. Fuck. Turn around. I want you to look at me when we cum." he said, as he moved back to take out his cock from Stiles' tight little hole.

Stiles was suddenly left with a feeling of emptiness. He wanted… no, needed Derek back inside. He turns around, and his gaze meets Derek's. "Please… Derek… I need you."

Derek smiles and fills Stiles' hole again.

Stiles lets out a moan, Derek's increasing the pace of his thrusts, both of them looking intently into each other's eyes.

Stiles' dick was begging for release. "Derek… I'm going to cum. I can't-"

"Me too. I'm going to cum." Derek moves back, letting his dick slide out, and takes off the condom.

"Oh my God! Ahhh!" Derek cums, leaving trails of his load all over Stiles' stomach.

"Ahhhh." Stiles is panting, as he also cums.

Derek falls on top of Stiles, and he nibbles on his ears before whispering. "I love you."

Stiles pauses and smiles. He smiles because he loves seeing this side of Derek, the soft and more sensible side.

"I love you too" Stiles whispers back. "Mr. Sourwolf." he adds, chuckling.

Derek rolls to his side, grinning, and puts one arm over Stiles' chest.

"So, was the surprise worth going trick-or-treating for?" Stiles asks.

"Hmmm. We should go trick-or-treating everyday." Derek smirks.

Stiles lets out a little laugh, before he moves in closer, feeling the warmth of Derek's body next to his.

And before they know it, they are both asleep, legs intertwined and arms wrapped around each other.