Rude Mother In Law...

I'm 36w2d and my MIL is so rude, we have a really good relationship but lately she's been making jokes that I'm the fat lady instead of just calling me pregnant. I've been brushing it off but she said it in front off almost everyone at the christmas party on Christmas Day and I almost lost my shit... I'm not even fat, I'm all baby this pregnancy and I even in fact fit my pre-pregnancy clothes still and have only put on 15 lbs since I got pregnant. With my first baby I was huge like bigger than I am with this baby and gained a good 40lbs with the first... Like my feelings are hurt and I don't even want to go back to my husbands mothers house now that she thinks this about me. I already feel like a whale as it is and being called fat lady on top of that sort of just makes me feel worse.