@boredgosleep
I also think it is very sad and unnecessary that you think this way: "I'm never going to be compatible with or accepted by your family so sadly you and I are going to have to part... walking on eggshells... people looking down on you because of your personal appearance..." 😢
Without wishing to be rude, and with genuine intentions, I feel that this has a lot of internalised self loathing. Just because someone notices that you are fat, that doesn't mean they dislike you, look down on you, or are incompatible with you. The same goes for any other physical attribute people notice about you.
Thanks: your comment is thought provoking and I can tell it's thoughtful so I wanted to respond thoughtfully, but I genuinely think you've read this wrong.
I think its the opposite of self-loathing. I have a policy that if people reject me or comment negatively about me or in any way try to put me down I walk away from them, usually permanently. I don't expect everyone to like me or approve of me (that's their right) but I do feel that its my right to protect myself from the arbitrary judgement of others. (For the record I'm not overweight but I've been on the receiving end of other types of arbitrary judgement and I just don't tolerate it, ever. It's one strike and you're out.)
My long experience of this is that trying to please other people or to fit yourself to someone else's idea of who you should be, what you should think, what you should look like, what ideas you should hold or principles to adhere to never ends well. I just don't see any benefit in absorbing or tolerating judgement from people unless they are people who I know well and trust and when I think there is genuine goodwill.
That doesn't mean I don't take criticism or feedback. But it means I have made a promise to myself not to have people in my life who will erode my sense of self worth by not properly understanding me or acting out their own hang-ups or prejudices on me.
If the OP had been with the boyfriend for many years and knew the family well and she was confident they meant well, then the position might have been different. But in this scenario, this is an early getting to know you meeting, with high stakes where everything is new and everyone should be on their best behaviour. And the parents of the person who the OP loves have chosen to be indiscreetly unkind and gossipy about her without taking care to ensure she didn't hear them.
Most people on this thread seem to think this is normal. I don't. I think its rude, shallow, unintelligent and completely graceless. A lot of people tolerate low level microaggression and unkind behaviour from people they know to keep the peace. I choose not to.
I wouldn't have expected anything of the boyfriend. But there's not a cat in hell's chance I'd ever have had anything to do with the family.