HIM "Most of my friends appreciate my brutal honesty. I tell them they are balding, that they need braces or whatever and they never get this sensitive. People tell me I am fat and I dont get mad"
"I'm not *most* of your friends. I don't appreciate it. Don't ever do it with me again."
"Here's some brutal honesty for you. You are rude and hurtful. Stop." (Dollars to donuts he's one who can dish it out but can't take it.)
The argumentum ad populum
is a logical fallacy. Just because lots of people believe it, or say it, doesn't make it true. He's rude, pure and simple.