I just returned from a spell with my H's family, and I chafe against these situations where I'm expected to act like nothing's happened, everyone acts like nothing's happened. I say, recognize that it's tough on you, get through it, and then take extra care of you. I say, when you're unsure how to be, think about it from your son's viewpoint and imagine what will be good for him on that day. I would imagine that cordial but distant yes/no, avoid interacting, is a good choice. You can always hold onto the little insults and details to vent here later, that's what I did. It does help.
I hope you stop comparing yourself to OW like there's a competition going on. You're your size and it's awesome. You're you and you're awesome. If you're competing with anyone, let it be with your own self, to be the best most well-adjusted self, with your priorities right. Size is nice, health and wellness and longevity are even better, and has nothing to do with whether OW eats tofu or weighs less. You rock, all on your own!
Adinva 51, S20, S18 M24 total 6/15/11-12/1/12 From IDLY to H moving out 9/15/15-3/7/17 From negotiating SA to final D at age 50 5/8/17-now: New relationship with an old friend __ Happiness is a warm puppy.