acceptable\not acceptable

Why is it socially acceptable for someone to say to my face” you’re to skinny, you need to eat more” but I can’t say “ you’re to fat, lay off the Twinkies” ;and another thing, why do fat people get to have handicap spaces, if they need to loose weight and I need to gain weight, make them park at the far end of the lot and walk off some of that fat and give me the handicap space so that I don’t have to walk as much and gain a little weight. Give elevators a lower weight limit and make them walk the stairs; that can be their goal, to ride the elevator. If I can't call you fat, SHUT UP and leave me alone.