Nah it's fake as shit. Dude just stands there waiting for his pants to be pulled down before deciding to fall into the pool.
huh? no. how do you know what that guy was doing standing there, where he was looking, who he was talking to? There is nothing fake about that stumble in heels. Too much to choreograph and time to stage it. It happened in less than a second--waiting to say hi to her, maybe, then she stumbles into him. You know what kind of balance that guy had? I don't. It doesn't really take much momentum to push someone back like that if they stumble into you, if you aren't waiting for it.
guys: just because it looks silly doesn't mean it has to be staged. all the fricking time. weird shit happens more often than people want to believe.