A/N: honestly, I don't even know. I just really wanted bottom Lucifer, and then my muse decided "hey, you've never written and alpha/omega fic before...this is gonna be that fic" so then this happened...not sure what to think really

also the time explanation. That's based off of Dean's 4 months in Hell being equivalent of 40 years...so me being the type of person I am decided in class to figure out just what that came down to seconds on Earth compared to Hell. I didn't have a calculator so it's rounded up to whole numbers

Warning: alpha/omega dynamics, heat, mating, impregnation, mpreg, slash, Bottom!Lucifer, Top!Sam

Archangels were considered Heaven's most powerful weapons. Of course no one knew of the secret amongst them, and why not? It was so well-kept, but really nothing can stay a hidden forever.

Lucifer is an omega. The only one of the archangels, though only few people were actually privy to that knowledge; three to be exact. One of whom is MIA, another who is dead, and the last person to know this secret has withdrawn into themselves so much that Lucifer doubts they're even aware of their surroundings right now.

Lucifer's been all by himself in Hell for a long time now. He's learned to deal with his heats when they come, of course that was when there were no other Alphas around. Before Sam Winchester swan dived into the pit.

Before Sam, his heats were short and mild, but since Sam so graciously took it upon himself to pull them both back for the greater good of humanity his body has reacted. It's as if it knows there is a viable mate for him in close proximity.

No this time when his heat hits him, it's a strong one. He wants to lock himself away from Sam and deal with it on his own like he's done for the past millennia, but his body is screaming at him, it wants to be mated it needs it so bad.

Sam finds him curled up on the bed shaking; it's not hard to find him. His scent is easy enough to find; it's coming off him like crazy, literally calling for Sam.

Lucifer whimpers when he sees Sam, his body feels like it's on fire, cock throbbing hard between his legs, hole already slick in anticipation of being fucked.

A smirk finds its way to Sam's face as he sees what state Lucifer is in, eyes darkening in lust seeing the archangel a quivering mess on the bed already ready for him. He's across the room in a few strides stripping off his clothes as he goes.

Sam is on the bed tearing off Lucifer's pants and spreading his legs, settling between them as he growls out "why didn't you tell me?"

Lucifer just shakes his head body thrumming excitedly, feeling a rush at being manhandled by Sam; those hands, those giant hands pushing his legs further apart.

"Answer me," Sam says more forcefully hand trailing up the angel's inner thigh.

Eyes wide and gasping Lucifer pants out, "thought…I could han-dle it..nev-er..never this strong before."

Sam just grins wider, hand moving till he's got fingers teasing at Lucifer's hole. "Look at you, already wet for me," he smirks taking delight in how the Devil beneath him is twisting and moaning in want.

"Sam…please," he manages to get out between moans.

"Please what," Sam asks head tilted as he feigns ignorance.

Lucifer whines, a high pitch keening sound at the back of his throat as Sam suddenly thrusts two fingers inside him. "Fuck me," he says breathlessly arching up off the mattress.

Sam nods pulling his fingers out and flipping Lucifer over pulling him back onto his knees, hands gripping at the fallen angel's hips as he thrusts forward buried himself fully inside. He grunts at the feeling of tightness around him giving the angel some time to adjust before he starts up a rhythm.

Lucifer's head is bowed, breathing heavily as Sam grips his hips, thrusting into him deeply.

"Should've told me," he grunts out, but Lucifer is in a fog right now.

The only thing his mind is capable of processing is moremoremoremarkmematemeclai mmefuckSamyesgood. It's a track on loop as Sam's hips snap forward, the human draping himself across Lucifer's back, teeth grazing over the angel's shoulder.

Gasping for breath he moans softly as Sam shifts his hips to bring each thrust hammering against his prostate. Breath warm against his ear, Lucifer shivers as Sam's voice, low and rough, starts up a running commentary of what he's got in store for the angel in his grasp.

"Look at you, so eager…begging for my knot," he pants out, voice sounding raspy as he thrusts hard in to Lucifer. "Gonna fill you up with my seed…you're gonna make me an heir," he growls lowly as he thrust in roughly a hand moving to Lucifer's flat abdomen.

Lucifer nods in agreement babbling incoherently because Sammy is boy King of Hell, why shouldn't he have an heir?

He's so close it hurts, cock red and throbbing left neglected between his legs. Whining he moves a hand to stroke himself for some release only to have it swatted away by Sam.

"You cum when I let you cum."

He lets out a high whine, fingers clenching at the bed sheets to keep from temptation as Sam continues his brutal pace.

Sam is getting close, his cock beginning to swell the beginnings of a knot forming forcing Lucifer's hole open wider to take him.

Lucifer cries out arching his back, he feel impossibly full right now, like he's being split open on Sam's cock. He's a whining mess, legs shaking to keep himself in position as he grinds back on Sam, so desperate to cum. His cock is leaking precum, twitching with the need to be touched, but he staves off his orgasm. He can't cum, not yet, not till Sam says.

With no preamble Sam grips Lucifer stroking him firmly, voice low as he murmurs "cum for me," and it's all too much for the angel. He's cumming hard, spilling over Sam's hand as he cries out Sam's name. Sam moans loudly feeling Lucifer clench around him, cumming a few thrusts later filling the angel with his seed.

Lucifer is whimpering slightly, slumped against the sheets feeling utterly spent. He doesn't even protest when Sam wraps an arm around his waist, tugging him backwards to flip them onto their side. Sam's still buried inside Lucifer, knot keeping him in place to insure a successful mating.

Time works differently in Hell than on Earth, and while Sam's down here, Lucifer is bound to sense time like Earth, even while Hell continues on its fast track. He feels time pass by in the seconds, minutes, hours of Earth, while Hell moves on two minutes for every second, 2 hours for every minute, 5 days for every hour.

That's why he knows within an hour that it took, that inside him is Sam's heir he wanted. Sam must know too, as he moves a hand possessively over Lucifer's abdomen, stroking the skin beneath fondly. Feeling spent Lucifer closes his eyes relaxed by Sam's hand over his stomach, allowing himself to sleep.

He wakes 9 hours later, sick to his stomach, and if he wasn't sure before, he definitely is now as he sinks to the floor by the bed throwing up in a trashcan.

Sam just smiles down at him eyes transfixed on the angel's stomach, already softening a bit.

The next few hours are like torture for Lucifer; he's sick to his stomach and just wants to curl in on himself. And then the strangest thing happens. His stomach gurgles, actually gurgles and he's looking up at Sam scared, not quite sure what that means.

Sam just chuckles rubbing Lucifer's tummy, "you're going to need to eat," he murmurs.

He just nods unsure of how to proceed; he's never had to deal with food before.

Sam feeds him, gives him spaghetti and chocolate cake all the while rubbing soothing circles over his tummy.

It's been 15 hours since Sam claimed him, the equivalent of 10 weeks in the pit, when Lucifer first notices the slight swell of how his abdomen curves.

His first thoughts are 'it's way too early for this', but then Sam is laying between his legs, face level with his belly, finger tracing over the swell murmuring "one, two, three," as he moves, finger stopping at each number.

Lucifer swallows nervously; three.

By nightfall he's got a definite bump, shirt stretched out snuggly riding up to expose a strip of skin, pants unbuttoned and partway unzipped, no longer fitting correctly. Sam eyes him licking his lips as he crawls onto the bed pushing Lucifer back a hand going to rest on the angel's belly as he kisses him hard on the mouth.

"Mine," he whispers in Lucifer's ear as he runs his hand over the bump and all Lucifer can do is nod so incredibly turned on by all this.

Sam fucks him that night. It's nowhere near as frantic as claiming had been, but by the end Lucifer is breathing heavily covered in a thin sheen of sweat as he stares up at the ceiling, Sam curled up on his side stroking his belly as they drift back to sleep.

He wakes up to the feel of Sam kissing his belly murmuring softly. Eyes opening he realizes he must have been out for quite some time as the bump is noticeably bigger. He moves to get up frowning when he realizes he doesn't have any clothes to wear deciding to wrap the sheet around him as he makes his way to their kitchen.

Sam chuckles, seeing just where Lucifer is heading for, but then again the angel is eating for four now. He watches in mild interest with a brow raised at some of the combinations the angel comes up with, and how he eats as if he's starved.

His body craves extra food for the babies, and he easily gives in eating his fill. Sam just smiles and gets whatever the angel wants. When he's done he stands up, still a little unused to the extra weight as he moves around to clean up some.

Sam wraps his fingers around Lucifer's wrist stopping him in the process of clearing the table and instead drags him back to bed. It seems he has other plans in mind.

Sam pays lavish attention to Lucifer's protruding bump. He kisses a path over heated flesh, hands on either side of the bump as he leans down tongue circling Lucifer's belly button. The fallen angel squirms a bit at the attention, but a well put hand to his waist stills him.

Sam uses only his fingers and his mouth to get Lucifer off this time. It's still mind blowing in Lucifer's opinion, has him thinking, 'it's always the quiet ones'.

He thinks he must have dozed off sometime after Sam swallowed him down, because this time when his eyes open he feels huge, and he looks it too. He tries to do the math, figure out how long it's been, but he forgets all about that as he feels something move and he realizes it's a kick.

Sam's eyes brighten as Lucifer takes his hand resting it to his belly to feel a kick.

When he gets up for food this time, he needs Sam's help to get off the bed, he no longer walks, but waddles as he moves in search of more food. He looks down at his belly deep in thought as he snacks on his pudding, wondering how much bigger he'll get.

He's coming up on the 48th hour since all this has happened, he feel big, surrounded by a sea of pillows propping him up in bed. His bellybutton once an innie has popped outwards standing out proud against his distended belly.

He squirms a bit on the bed huffing out as he tries to get comfortable. Nothing seems to work, between the children kicking at his insides and how his back is throbbing in protest; he's just counting down the time left.

Of course sitting on the bed and waiting things out was never going to be an option with Sam around. The younger Winchester crawls on the bed settling between Lucifer's legs, and while he's feeling uncomfortable and just entirely too large, he's eager to see what Sam has in store for him.

Grinning up at Lucifer, Sam leans forward pressing a kiss to the angel's large belly, trailing his tongue over the protruding bellybutton earning him a gasp from the pregnant angel. Repeating the action he distracts Lucifer as he moves his hand between the angel's legs a finger slipping up into the newest entrance.

Eyes wide Lucifer whines softly hips jerking up as Sam teases him. It only serves to spur Sam on with his ministrations. He quickly dissolves Lucifer into a withering mess the angel begging to cum, to have Sam in him.

Sam doesn't disappoint pushing Lucifer's legs further apart as he thrusts inside taking the opportunity to lick at the angel's oversensitive nipples. Lucifer doesn't last long before he's clenching around Sam gasping for air as his orgasm washes over him.

Later as the cum is cooling on the inside of his thigh he allows his eyes to droop shut feeling Sam press a kiss to his temple murmuring "soon" hand running over his belly.

The next time he wakes it's to a rush of water down his legs and a sharp pain. Hissing out as another contraction rips through him he grabs for Sam's hand, finger's digging in skin with a vice grip.

The birth is painful and messy, but it's worth it in the end when he's got a boy and a girl in each arm as Sam holds their last child a baby boy moving to sit on the bed.

They grow quickly, by the end of the week they're three and a half. At two weeks they're seven, and when they hit 10 their growing begins to slow, becoming more regular.

Lucifer thinks Sam doesn't notice, but nothing escapes the young Winchester's sight. He sees how Lucifer will watch over the children, how his hand unconsciously moves to his tummy. The way he fidgets, pulling at the hem of his shirt, or how when he's in bed he curls up with a pillow to his chest.

That's why when Sam crawls into bed that night he wraps an arm around Lucifer's waist, palm flat against the angel's belly as he whispers, "how would you like another one…or two?"

In response Lucifer pushes Sam on the bed straddling his waist as he sinks down on Sam's cock inhaling sharply at the sensation of being filled.

Later that night when Sam's knot has dissipated and he slips out of Lucifer curling around the angel his hand finds its way back to Lucifer's belly. The touch fills Lucifer with excitement because he knows deep down that he's pregnant again.

"Not the last ones either," Sam mumbles sleepily and Lucifer smiles snuggling into Sam's hold hoping that he's right about that.