It's stupid, the way that makes Stiles' stomach flip over and coalesce into a warm puddle.
"Well, good," he mutters. "You deserve to have fun. You deserve to have a nice life, Derek, after everything that's happened." And he probably shouldn't bring up that other universe, if he wants Derek to stay happy.
He clears his throat, knocks his foot playfully against Derek's under the table, and raises his eyebrows. "And anyway, I know you're a nice guy. The whole bad boy don't-fuck-with-me thing might be universal, but I'm betting the nice guy part is too. I've got your number, Derek Hale." He smirks and sits back, meets Derek's eyes. "You care, even if you don't know how to say it."