The tone might not be flirtatious but the words still were. He hid is grin in the edge of Stiles' shoulder without shame.
"There might be something I want that you'd say no to, but I'm hoping we don't come across anything either." To say that he was into it wasn't quite accurate -- he was into Stiles. And he'd be more than happy to help his mate achieve his fantasy and enjoy every second of it.
"What part -- or parts -- are you having problems deciding about?"
The kissing wasn't designed to arouse at the moment, it was more affection than anything else, and Derek watched for a few minutes before pressing his nose into Stiles' cheek. "Yes. I was born a werewolf, but my mother was one. To have a werewolf child one or both parents have to be a werewolf, either born or made. Some packs have multiple alphas -- in hierarchy, not orientation -- but they usually aren't healthy packs. But then you also have kids that have been bitten and that have human parents -- and they might opt for a different alpha. Or if their alpha has been killed -- there are a lot of reasons why they might not have one, or might switch packs--" and he grinned, big and stupid at Stiles calling himself mom.
"Mom or human daddy?" Because he remembered that Stiles didn't want to be feminized, and he very much liked his very male mate. And he also loved the thought of them having a swelling pack, not just with their kids but with with others-- and he rubbed his mouth over the edge of his shoulderblade messily. Not sorry.
It was impossible to notice when Stiles moved away, even if he couldn't smell that hitch in his scent. "Yes," he hissed out. How could he explain this? He listened, and then shook his head slowly. "Partially, but you have a familial bond with one another. He's an Alpha, and he's probably acting more like your father right now than your brother. He'll never see it that way, but he is. I should have presented myself as your suitor and he'd be having a much easier time now. I'll deal with that tomorrow."
This was important to Stiles and thus, important to him. He went quiet again, listening, his brows drawing up slightly. He'd never heard of that before, but he'd never been mated either, but it made sense. The sadness in the shower. Now, the faint tinge of uneasiness rolling off his mate.
His fingers stroked up and down Stiles' side, eyes shutting fast as he finally eased out of his mate and immediately tugged on him so they might be face to face. "I'm glad to know you want this, but I'm worried about this hurting you." That was one thing Derek never wanted. "Maybe it means your --" that there was something wrong with the birth control. "We should call Deaton, just to make sure."