HIYO, female insect peen coming at ya!
This is a closeup of a Brazilian cave insect in which male and female sex organs are reversed. The males have vaginas and the females, big ol' penises (for an insect). The male still produces the sperm though, the female just dips her penis-like straw (called a gynosome) into his vagina to collect the little swimmers. Why we should count our lucky stars we weren't reincarnated as male Brazilian cave insects:
During mating, the female's spiny penis gets tightly anchored to the male vagina's sperm duct, allowing the female to receive the semen. In other words, this penis functions more like a straw than a spout. If the male tried to break away [during copulation, which lasts between 40-70 hours], his abdomen would rip open, and he would dramatically lose his genitals. These female insects also mate with multiple males and can store two batches of sperm in the body.
Wow, Mother Nature -- you've really outdone yourself. Nothing like having your abdomen ripped open and "dramatically losing your genitals" because you tried to get up and grab a bite to eat in the middle of a 70-hour sexcapade. Listen, here's a little protip for all you male Brazilian cave insects out there: just masturbate.
Keep going for a shot of the organs mid-copulation, and a diagram explaining what you're looking at.
Thanks to Thaylor H and lilco, who are both thankful they aren't any kind of cave insect. Same, I would be one of those blind cave salamanders though (but only for a day).