Oddly it was a science teacher explaining that in apes, testicle size correlates with how faithfully a pair stay together. The more devoted to one another they are, the smaller the male’s testes. Chimps aren’t devoted at all, they are rapey fuckers.

But being a high school, that went into penis size and I could remember gorillas weren’t very big but not how small they really are.

Fun(?!) Fact: Apparently a Gorilla penis has no urethra, and looks like a deflated purple balloon when not “in use”. (I didn’t find a picture, a biologist on one of the sites I googled described it that way. Feel free to look for pics but I’m not.)