Why do our bums have a crack?

Why can't it just be a big round mono-bum?

Hmm...then how would the bad stuff get out?

Through the hole...same as always The crack is only there for decoration

To get a sexy look..

lol I have no clue

I don't know but I have a theory.

I think it is to give our legs better range of motion. If the skin went straight across the action of walking would cause the skin to have to twist and stretch. Each buttock having its own skin covering allows them to have more independance.

Just to make ammusing people like you ask that question.
I find it rather random it has a crack, everytime someone moons me im like 'woah yours has a crack to' just because im sometimes silly

...because it conceals the butthole. Which is VERY important.