She thought you were looking at her ass, so it wasn't that big of a deal... but you're looking... at her FEET? She can't help but laugh and pick on you, disgusted at the fact that you're not turned on by a "normal" body part. It has to be something SWEATY and stinky, like her feet. Well, ENJOY them, at least until she finds a movie to watch for the night. And after that, you're SOL.