Sounds like water's traveling through your balls

A phrase used to say someone is so stupid that they can't even reproduce, they just have water for sperm because they can't even do what all living things are supposed to be able to do. This can be used to talk about women to say that they are stupid, but it's mostly men.

"Like I said before the Bible says the Earth is flat."
"You're going through the same arguements with no other evidence, it sounds like water's traveling through your balls, man."