*shudder*
Yeah, but it's grosser than that. The guy lets the partner do the business on them, and then has them spit it into HIS mouth, so that he can swallow it.
It actually led to 'The Question' in the movies when a girl casually explains this to her boyfriend, after calling a guy 'Snowball,' and suddenly he's rather upset, and wants to know how many guys she's been with.
Anyway, grossness. I'm glad Krazi explained it, so I didn't have to. Sort of.
-kv