three seven said:
"I think we should get married."
"Taxi!"
That's by far the best I've heard.
My friends and I often consult each other on these situations. Usually, they - not being writers - ask me what they should've said, and I can come up with something pithy and brilliant. Me, on the other hand... I'm terrible in the moment, and I always come up with these nuggets of genius later, but then the editor in my head plays with it until I come up with the
best possible response - usually a week or two after the entire incident (when surely the other person involved has long since forgotten about it).
All those moments (and there have been hundreds, if not thousands) are gone, as the only thing in my brain is MISUNDERSTANDINGS. Amazing how being on the spot can make you forget every embarrassing moment, fight, blunder, etc.