If I knew him at all and was already aware that he was a little socially backward, I would've laughed and said, "You know, you're probably the first guy I've ever encountered who thought big boobs and big hips with an itty-bitty waist looked weird."
One phrase I learned here that I absolutely love when dealing with people who've said something rude: "Oh dear, do you realize you said that out loud?" I've had only a couple of occasions to use it since I read it, but boy, do I love it--gets the point across without stooping low enough to throw my back out.
People ask some weird crap. Try not to let it influence how you see yourself in the mirror. The LAST thing you should think is, "Oh noes, there is a man out there who thinks a little waist and big ta-tas is funny-lookin'!" Big deal, his loss, move forward.