Cats are a strange breed of animal that seem to defy all sense of logic and rationality. Yet cats have a logic of their own that ultimately makes sense. Take the case of cats turning around to show you their butts. If people did this to you, you would slap their face, but when cats do this, it’s accepted if not liked.
The reason cats show you their butts isn’t because they’re mean but because cats sniff each other’s butts as a way to confirm each other’s identity. So when a cat turns its butt to you, it’s actually a polite form of greeting (and a sneaky way of telling you that you’re a peasant in the eyes of the cat).