Season 6, Episode 20: "The Doodle"

Oh, man, did you see that?

I ate discarded food.

-Well, I've done that. -Yeah, but with you it's intentional.

-Haven't you kissed her? -But this is different.

This is like semi-digested foodstuff.

The next stop is the stomach, and you can take it from there.

Oh, excuse me. Just a second.

Yeah, that's it.