"I'm not worried about him getting pregnant before me," Stiles replied with a frown. "I'm worried about him getting pregnant at all. He's going to have heats, he's going to have sex, there's nothing to stop it, Derek. And if he's not mated, or if it's someone he doesn't even know- he's not in the right place to have pups." He liked the soothing touch on his belly, he liked the way the way Derek held him, and it was kind of helping his anxiety. "I'm not that selfish, Derek. I can cope with having another omega around-" just in case that was in any doubt.
"And- Derek, Scott's an idiot. I love him to death, I really do, but he's a total moron. Isaac could have a flashing sign over his head that said 'Scott, I'm your mate' and he'd still be confused. I don't want him to fuck up. I don't want Isaac to get hurt." And he didn't want Isaac in bed with them. It wasn't going to happen, he knew it wasn't going to happen, but the idea had come up such a short time ago that he was still jittery over it.
He sighed and leant back against Derek, into the warmth of his body. It would work out. Everything would be fine, he knew that. At least he had Derek to worry with. Calm, sensible Derek.
"You're a great Alpha," Stiles whispered. "You're going to be a great dad."