Someone who is a terrible driver. For example, speeding, going off the road constantly, and paying more attention to whats happening inside the car than what is happening outside.
When you’re engaging in doggy stylevaginal intercourse and you insert your thumb in the woman’s asshole and with your fingers raised, move your hand left and right as if your hand is on a steering wheel.
Bus Driver's Bum
Have you ever seen a bus driver with a small arse - no, because they are always sat on it!
So this applies to someones whose arse is that bloody big, that it can easily effect tides and cause a solar eclipse.