Is it ever acceptable for people to insult their friends?

I'm not sure that this was an insult. It sounds to me more of an observation. Gorgeous and polular men and women can be fickle, irrespective of the attractiveness of who they are dating. It sounds like the friend was just trying to give some useful advice. My own parents told me to avoid "good looking no-good men," and I am sure they do not think I am unattractive. They just know people. As for friends insluting eachother, I'm English and in my country people give eachother joking-non serious insults all the time. They only do it to people they like- and it isn't meant to be offensive. It's just gentle mockery. I love it when people inslut me. My ex came out with a classic. We were watching a large and ungainly female comedian prance about to a Tina Turner song on TV. I said "That's your next girlfriend." He said "Of course, you always go for someone better than the last one you had." I laughed my butt off for ages. It was meant as a joke, and I took it as one.

well, I'm wondering what you mean by insult of the friends. Personally I make fun of my friends. It's all in good fun and they do the same to me. It's part of friendship. I've told my friend she has lame friends and she always likes bad guys. It's joking, but it's also truthful in some ways as she divorced her husband and realized some things about other guys she's liked. I also think in friendship there should be honesty... hence why friends can say things like that to each other. I'd say if her friend went for popular and gorgeous type of guys than maybe that was her way of telling her friend that she went for the WRONG types. Just because a dude is gorgeous and popular doesn't mean he's right for you. So maybe she wasn't meaning her friend was lame and ugly, but just that she needed to go for guys who were more than an outwardly appearance.