Guys, would you tell your friend if you thought his girlfriend wasn't attractive?

If I had a friend who asked if I thought his girlfriend was attractive and I didn't think she was, I wouldn't tell him that. It doesn't matter whether I thought she was attractive or not, she's not my girlfriend and I would consider who she is and how good she is for him more than how she looks. I would tell him that she is not really my type, but as long as he is happy and content with her that's all that matters.