Derek can't help but to smile a little, because Stiles is just so bright and full of life, and sometimes it feels like it's thawing Derek out just sitting next to him. Stiles is an inextricable presence in his life now, anchor no longer anger but the boy sitting at his side, and Derek can finally admit that to himself. It's too soon to tell Stiles that, though, so Derek keeps it to himself, locks it away in his ever-thawing heart until Stiles is ready to hear it.

"You're gonna need to work on your petname game if we're going to make this work," he tells him, doing his best to sound casual while being glad Stiles can't hear the rabbit quick thump thump thump of his heart. He bumps their shoulders together and turns to give him a teasing smirk.