"DEREK!"
Derek was pretty sure he heard the windows rattle in their panes and birds fly away in fright of the sheer volume of Stiles scream. Derek covered the smaller man's mouth with his hand. He could feel Stiles struggling but they were still knotted together and there wasn't much Derek could do until his knot went down and they could separate.
"Stiles, please calm down. I know I should have told you. I'm sorry, but please can we talk about this after my knot reduces and we can talk through things calmly." Derek said his peace in a kind of quick hush. When he felt Stiles relax he let his hand fall away from Stiles' face. He waited for the younger man to do something, say something or even scream at him again but nothing, there was just silence. Derek waited for the better half of two minutes before saying, "Stiles?"
Stiles let out a breathy laugh. He was staring at the empty space in front of him with a shaky hand delicately pressed to his abdomen. "So it's true, I can get pregnant." It was a question, nothing in the words called for a response they were definite and dropped like a stone.
Derek replied anyway, "Yes it is possible technically because Alpha DNA yields to the continuation of the pack. If I take on a male mate, which is more commonplace than most people would think, then its possible. But our pack is large and strong I don't see there being any reason for my whatever controls this to take effect.
TEETH
Stiles lay there trying his hardest not to twitch and fidget as he was acutely aware of the cock that was still plugging his ass. He heard Derek apologizing to him but it barely reached him he slumped in defeat as if he had thrown all of his energy into that initial yell and now there was nothing left. Derek took his hand away and they sat there in silence. Stiles was thinking of everything and nothing all at once, he wanted to say something but the words refused to form in his mind. When Derek said his name he was pulled back into the now.
He repeated information that Derek told him dumbly. He couldn't think of anything else to say. What else was there to say? Hs partner kept talking. Stiles still couldn't fully process the words but he felt them as they vibrated through Derek. He then noticed that one of his hands were pressed to his stomach. He didn't notice until then but he looked down at his stomach imagining what it would be like to have a baby in it. The thought was both horrific and pleasant. He knew Derek wanted a big family and he hated the fact that he couldn't provide that for him because of his gender but then again if he was pregnant where was the baby? To his knowledge he didn't have a uterus or like eggs to even fertilize. How would he even have the baby? He definitely didn't have a vagina and there was no way a baby was going through his pee hole, or would it come out his ass? It seemed more logically because that's where Derek spilled his seed, that's where Derek knotted him, and currently that's where Derek was pulling away from him.
Apparently while Stiles was lost in thought some time had passed because the swelling of Derek's knot was no more and they were able to separate. As soon as Derek was completely out of the younger man he slid out of bed just to get up and sit on the edge of Stiles' side. He looked down at the boy.
Stiles looked up at his mate as soon as he felt the mattress dip next to him. Stiles finally spoke a coherent sentence, "how long until we know?"
Derek looked down at Stiles shocked to see the emotions that ran across his face in the short amount of time it took him to speak the words. Vulnerability and longing took over Stiles entire being where Derek thought he would see hatred and anger. He realized that Stiles was expecting an answer and thought about it. "Well assuming that it goes similarly to a female getting pregnant with a werewolf baby, a week maybe 10 days." Derek was about to add on that if Stiles wanted to go to Deaton and get rid of it he would understand but something in the way Stiles looked at him and clutched at the flesh of his stomach told him that wasn't a wise decision.
"Stiles, you might not be pregnant. It's not exactly a fluke thing but it doesn't happen every time," Derek watched as Stiles face fell a small bit before he controlled his features. Derek was still confused as to why Stiles was like ripping his dick off and shoving it down his throat, "Stiles, what are you thinking right now?"
Stiles looked up at Derek then sat up and crossed his legs Indian-style so that he was relatively level with Derek. He opened his mouth to tell Derek but then shut it, he didn't want to think he was being stupid or anything of the like.
Derek moved so that he was facing Stiles more squarely and he took the human's hands into his own, "it's alright, you can tell me."
Stiles was torn but finally gave in, "I-I know how much family means to you and if I had this chance to give you a family I would take it in a second."
Derek stared at Stiles, pride and joy welled up in his heart and suddenly he realized he was staring too long. The alpha lunged forward and scoop Stiles into his arms. He immediately nuzzled into the spot just beneath his jaw and whispered, "thank you so much Stiles. Please, don't feel pressured to do this for my sake if it's not something you want….but thank you."