Season 7, Episode 16: "The Shower Head"

Hey, you're not giving it to me, man. What's wrong?

I just took a bath, Jerry. A bath.

-No good? -It's disgusting.

I'm sitting there in a tepid pool of my own filth.

All kinds of microscopic parasites and organisms...

...having sex all around me.

Well, you used to sit in that hot tub.

Jerry, that was super-heated water. Nothing could live in that.