Why Humans Evolved Big Penises But Small Testicles
Balls Big! How to Make Your Testicles Bigger!
It is argued that those mammals with internal testes, such as the monotremes, armadillos, sloths, elephants, and rhinoceroses, have a lower core body temperatures than those mammals with external testes.
A woman will look for several other clues that a man has the genetic stuff to pull this reproduction off, but none is more important than big balls on a man.
So to ensure that children are able to reach maturity the male is likely to stay to protect them, both socially and physically.
Both penises were fully functional; he could urinate from either and get a boner in both simultaneously.