piss boner in the morning, great fun walking backwards while pissing and aiming for the toilet, then while still pissing and losing hard on walking forwards and still keeping your aim on.
Men are up for any type of challenge, tis good fun but when you get the bidirectional spray (ie you're a bit stuck together and there's two streams) there's a bit of a panic and a bit of mopping to do.
But that guy intended to do that, generally he'd need to be about to burst for that to happen or he held himself to make him last longer, but very hard to do that unintentionally.