It depends on the context and the person saying it. There are several ways to say it in a derogatory manner or a familial manner.
I've made reference to same parents that they have a fine boy, when referring to their young soldier. I've never had a parent, or their son, see it as anything other than a complement.
I don't really mind, you'll always be a boy to the elders that watched you grow. My grandma is kinda like that, even though I'm much taller than her now.
It's not that big of a deal, but I'd say calling a 18 yr old male a boy is a bit insulting. How about "young man"? Or does that make me sound really old.
You're just really old Phil. LOL
I was a boy in my twenties. Thought I knew stuff, when obviously I still had much to learn about becoming a man.
My son's, will always be my boys and so will all of their friends. If they are "men", they have no problem with an older person calling them boys.
Ha Ha Ha! Now that's friggin funny!!
I'm easily entertained by even the smallest wit. Ha!
I don't think it matters much.
I don't know! As Will said sort of said, it really does depend on the circumstances in which one is calling a young "adult", OR an older person a boy or a girl, or referring to them that way. People use those references all the time without any offense intended or taken.
Unfortunately it has become more of a political and racial question thanks to political correctness. The word 'boy' is not offensive otherwise.
Fuck off, boy. Wait... What...
Age doesn't matter. Some "men" will always be boys...and I don't mean that in a good way.