When I was really young I hooked up with this guy and he was skinny, eating disorder skinny, and after hooking up he implied that I was overweight and suggested that I should skip dinner.

Even at the time, even with how messed up I was, I just sort of laughed at him and said "yeah sure dude." IIRC, I was around 70 kilos and 6 feet tall so not fat at all, just like you with a bit of belly fat.

He also said something along the lines of how I shouldn't be ashamed of my size and, again, knowing I was 6 inches, was sort of taken aback. He waa maybe an inch longer. It's possible he was negging me, but why when we'd already fucked?

Anyway, some people, especially young people, have a distorted and unrealistic expectation of the human body. Porn, movies, they're all to blame.