an old con gag that will always be funny is someone cosplaying spy from tf2 in a group of people and they've got a different cosplay taped to their face to blend in

Thin people are absolutely relentless with this. "But I have to TELL them!" "I can't just not SAY something!" "We can't just PRETEND it's fine to be fat!"

I genuinely think it's related to what I observe about singleness, virginity, and ace/aro topics: people's entire worldviews are threatened by fat liberation. And having your worldview challenged is scary... especially because so many people have put so, so much personal effort into Not Being Fat, so much self-hate into gaining weight, so much self-denial of food they like and forcing themselves into activities they hate, to avoid being fat.