In the UK lemonade is a carbonated soda. I thought that was the root of the joke, with a cultural confusion. The other commenters seem to think it's a pee joke? But if it was, it wasn't funny so I think I'm right.
That said, my interpretation isn't funny either? What is this post?
He was always in a coma. The fake tits woman is a dream and therefore not real. It's got the bones of a joke, but execution was confusing.