All thanks to the wonderful muscles of the human ass. I can’t help but laugh sometimes.
Huh. Can’t help but wonder if this is connected to why a significant amount of people find asses sexually attractive across gender lines - something about signs of a good persistance hunter (likely quite overstated by base monkey brain), and therefore ability to provide for spawn.
Probably not, but makes ya think. I also accept that I’m thinking about it from a heteronormative, sex as biological imperative for spreading genes POV - so limited and overall probably wrong.