Yeesh, so many people grumbling about poor relationship dynamics. The whole joke is that it was all in his head - she teased him a little, and he put himself into a tailspin by losing an imaginary argument.

I've done that kind of thing a few times myself - my wife says something innocuous, and I read into it until I've gone completely off the rails. Has nothing to do with anything she's done, it's all to do with me misreading what's happening and forecasting wrong without checking anything. That's the joke.