[He didn't want to ruin the afterglow with his own insecurities. After all, they were just doing the friend thing; it wasn't a serious relationship where they talked about their feelings. So he returns to the usual smile, plans to pepper in a joke here or there, and hopefully she'll be none the wiser.]

Just mentally giving myself a performance review. Probably needs more fireworks. Or acrobatics. Next time, I'll have to get us up on the ceiling, make it more exciting.

[Assuming she'd be interested in a next time after such a safe encounter.]