Jean-Paul is good at sneaking up on people because superspeed. The rush of air that comes with the arrival of a speedster of course is a dead giveaway as to what has happened, but he can manage to whisper "Boo," in David's ear before the wind catches up with him.

Fastest man alive and all.

He laughs brightly and steps back. "David! Isn't this a lovely surprise! No hockey nets - I checked - but delightful nonetheless. Come on, let's go around that bigass tree a few times."