system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the biological advantage to urination occurring in or near the sex organs?
gpt
You don't poop from there.  
Go further back in the evolutionary timeline, and you see where we branched off from fish. Some of the early cartilaginous fishes have a cloaca, a single hole they use to pee, poop, and make babby.  
So, it's a step up. Waste gets sorted based on sterility, so you don't risk your gonads to infection by coliform bacteria. Anything more clean would require a much more intensive shuffle of holes and tubes, and that's not how evolution works.