The Big Bang Theory Season 5 Ep. 10 (The Flaming Spittoon Acquisiton)
Sheldon: I believe, I would like to alter the paradigm of our relationship.
Amy: I'm listening.
Sheldon: With the understanding that nothing changes whatsoever, physical or otherwise. I would not object to us no longer characterizing you as "not my girlfriend".
Amy: Interesting.... Now try it without the quadruple negative.