Never. My 50-year-old dad wore short shorts for the first time to go to the park and I was so scarred. It's just so wrong, even on young people. Men's thighs are not the most attractive things out there ...
no eww not ever
Yes, it would make me laugh and lighten up.
No, I don't think its nice at all even if you have a good body and nice legs.
They're not the most fashionable thing, but they are entitled to wear whatever they like, as long as they're not exposing themselves!
I wouldn't recommend it though..