Totally reminded me of this:
Rimmer: Just cause they're aliens doesn't mean to say they don't have to visit the little boys' room. Only they probably do something weird and alien-esque, like it comes out of the top of their heads or something.
Lister: Well I wouldn't like to be stuck behind one in a cinema. http://www.imdb.com/title/tt0684161/quotes?qt0253923