What is the worst response to "I love you"?

Have you seen that episode of Friends where...is it Ross? I think it is Ross, who says the three famous words (and no I don't mean "food is ready" or "football is on" or anything nasty) and gets a "thank you" as a response. Have you seen that? Or am I out biking? (swedish saying) Maybe it was somewhere else, well anyway you got the point, right? Is thank you worse than a laugh? Worse than a shut down? Maybe thank you is synonomous to a shut down. Silence? What do you answer if you don't feel the same way? The weather is nice today?