whywouldagirlhaveapenis said:
Femme_Fatale said:
... due to the fact that they have more ribs than women do ...
...Really?
Sorry, not count, but size x.x
Females have smaller and rounder rib cages. Additionally, females also have a longer lumbar curve, though not too sure how that affects flexibility besides the pelvis being lower. However if you have an accident or a mutation that changes your rib count, that will affect your ability to perform auto fellatio.