Stiles hadn’t really tried all that hard to argue when Derek had practically begged him to use his magic to restore the tits he’d had briefly after having their son. Since the day they caught Nate with Bones, their entire dynamic in the house had changed. Nate had always been affectionate and cuddly, but there were no more closed doors to stop him from crawling into bed with them in the middle of their fucking, sometimes joining in during their touches. Bones had been more active too, and Stiles would be lying if he didn’t admit that Derek and Nate had been right, that dog definitely had a way with his tongue. And also his knot. Derek’s was fatter, more filling, but damned if there wasn’t something deliciously depraved in getting on his knees for their pet while his husband and son watched, taking that doggy dick up his ass and milking it for all it was worth. And he got the added joy of watching his husband take it sometimes too - and of the two of them helping Nate work up to it - he may be very young, but he was a werewolf just like his daddy, and his body was built sturdier. It was fucking obscene, watching his little boy take that big doggy cock and knot, and it usually led to him and Derek wrestling with each other for who got to suck the doggy come from their boy’s hole.
Nate also had a habit of trying to nurse again, something he hadn’t done after that first year - and Derek’s eyes always got darker while he watched their son try and suckle at Stiles’ small nipples. Which of course led to him admitting he wanted to watch their son nurse for real again, wanted to be able to see his mouth stretched wide around his papa’s tit, milk staining his face. And Stiles had protested that it was a hassle, an ordeal, something that took a lot of effort and was hard to hide, especially if he made them bigger this time, like Derek wanted. But the arguments were only half-hearted, because Stiles’ cock twitched when he thought about giving himself some nicely sized tits and then letting his son suck on them, mouth latched on a nipple, maybe while Stiles played with the boy’s hole. Derek smirked because he knew he had Stiles when he smelled the burst of arousal that came from his thoughts. So Stiles took a week off work, told Derek this wasn’t going to be a permanent or common thing, and growled that he meant it when Derek merely smirked again.
All of that led to now, to Stiles braced on his hands and knees on their bed, Nate laying beneath him, small mouth hungrily licking and sucking at the nipple of one of his magic made tits. The other was brushing against the boy’s face, both of them hanging down, fat and full and aching, while Derek slides his long cock deep inside of Stiles’ ass. The angle has Stiles’ hard cock brushing against their son’s little one, over his belly, leaving streaks of precome in its wake as Stiles moans, nipples tingling and ass clenching down while Derek talks in his ear.
“Such a good papa, letting our baby boy nurse on your tits. Knew you’d love it, love me fucking your hole while you fed our son. Can’t wait to see him grow up, fuck his little cock in alongside mine while he nurses from you. Bet we can knock you up again, get you pregnant with your own grandsons. You want that baby, want to feel your boy deep inside the asscunt that made him while you nurse the sons he gave you?”
“Hnnggg,” Stiles is so beyond words, mouth dropped open and panting. Nate switches nipples, his small hand reaching up to play with the wet tipped one he just released, pinching and twisting it and making Stiles cry out. Derek’s still speaking in his ear, cock thrusting hard and fast as he approaches his orgasm. Stiles wants Derek to knot him, but he knows his husband has other plans for today, can feel the strain in Derek’s muscles as he fights the knot back, and he rocks back into the thrusts, trying to help him along. Nate starts sucking harder, the milk must be running low, and the smacking noises seem to be the final push, Derek holding his hips tight as he slams in one last time, cock twitching as it pumps Stiles full of come.
“Nate, son, come here.” Nate only whines a little when Derek makes him unlatch from Stiles’ tit, and then Derek’s pushing at his hips, forcing his ass lower. “Wanna feel what Daddy feels when he fucks Papa?”
“Yeah son, scoot closer. Papa, pull your cheeks apart, show our son your hole.” Stiles adjusts down to his shoulders so he can reach back, spread himself open. “This is where Daddy and Papa made you baby, Papa grew you inside. Bet he’d love to feel you back in. Go on son, grab your little cock and balls, mhmm, just like that. Yeah, now scoot closer, be careful so you don’t hurt yourself, but just push them in, don’t worry, Papa’s ass can take it.”
Stiles feels his son fumbling at his hole, hooks his middle fingers in on either side and does his best to tug himself open a little more, making it easier. He gasps when he feels the brush of his son’s cocklet, feels the boy push it in, followed by his little empty sac. He wishes his son could get hard already, can’t wait to be fucked by him for real. Derek was right, he wants everything he said, wants to use his magic to be receptive again, let his little boy knock him up, wants to be pregnant again, know it’s his son who did it to him. His cock is hard and leaking and he misses most of what Derek is saying to Nate, but he can feel the way his son is grinding against him, does his best to clench down gently, give him something tighter to rut into. Derek slides beneath him, grinning up darkly as he opens his mouth wide, starts suckling on Stiles’ tits, alternating between them and practically worshiping them all while whispering up at him between sucks.
“So lucky to have you. How long do you think, before his cock can get hard, before he can fill you up with his little boy come and knock you up? Want to watch you grow round with his pup. Gonna have to stop fucking you when he’s old enough, want to make sure. Gonna make sure he’s the one who knocks you up, let him and Bones fuck you, I’ll just use your mouth. Maybe get you to keep these tits, fuck my way between them too. Come on papa, come all over daddy while I suck your tits dry and our little boy fucks your needy cunt.” Stiles rolls his hips back into Nate’s clumsy thrusting grinds, his cock rubbing against Derek’s spent one as his husband sucks on his nipples, dragging the milk from him. And Stiles wants it all, hopes it isn’t too long before Nate can take him just like his daddy does. Thinks maybe he can find a little more magic to make it happen sooner, especially when he feels his son shudder as he grinds in, his small body clamping around Stiles’ like an octopus as he ruts through his dry orgasm, mumbling about how wet his papa feels, how excited he is.
He’s unsurprised when Nate crawls back beneath him, curls onto Derek’s chest and takes Stiles’ free nipple in his mouth. Derek reaches a hand down, starts playing with Stiles’ hole, knows he’s close but just smirks when he suddenly moves his hand away and makes Stiles whine. He’s about to start bitching about being the only one left out when there’s a cold nose prodding at him, followed by a heavy weight as Bones hops onto his back, hips hunching and humping the air until Derek reaches around and helps guide him in. Stiles cries out, arches his back, briefly smothering Derek and Nate with his new tits as the dog’s cock nails his prostate.
“Maybe we can see if there’s a way for Bones to knock you up too - would love to see you stuffed full of pups, watch them nurse next to the others.” It’s the dirtiest thought Stiles thinks he’s ever heard - even more than getting fucked and impregnated by his own son, and it’s enough to push him over the edge while Bones slams away at his ass, relaxing enough as he comes down that he almost doesn’t realize he’s being knotted until it’s done. “Gonna have to show Nate how to nurse from papa’s ass too, looks like your tits are tapped out for now.”
Despite the lack of milk, Derek and Nate keep flicking their tongues against his nipples, keep sucking on his tits, while Stiles rides out Bones’ knot. He can’t say he minds, his body twitching through aftershocks of his orgasm every time they hit the right spots. He’s got a few more days of the magic, can’t wait to have one or both of them attached to his chest until the magic goes away, can’t wait to see how much further they can take it.