I don't really "get" this. Making it short was probably a good idea. What "thinness" was the belt referring to? I did appreciate the animation in this. I was afraid it was going to get really sexual. I should have known it wouldn't be too bad what with the way it didn't have an "A" rating.
While just one joke, it worked okay for itself. I like her expression at the end. It gives you the feeling of goofiness. Seeing as how the cartoon started off serious, it needed that. Then again, I liked that same weight gag.