What's the similarity between a fat chick and a moped? They're both fun to ride until your friends see you.
Are you saying that it's embarrassing to admit you had sex with someone who is overweight? I find that upsetting.
I think you are completely stupid not to think that fat cows deserve to be talked about that way.
It is perfectly fine if you don't find fat people attractive, but to joke about using them is not okay. Instead of putting other people down because of their weight, you should try to understand how difficult it can be to lose weight. Someone being overweight doesn't make them any less deserving of respect.