Phrasing matters. Men are adults girls are children. That may not be your intention but try to be mindful in how you interact with others and you may have more success with relationships.
You’re free to refer to your friends however you like, that’s the business of you and your friends.
Referring to “men” and subsequently “girls” in a general sense is very much a patriarchal view, implies women are inferior, and generally not respectful. I’m sure that’s not what was intended but it’s those sort of things that can rub people the wrong way, especially as a first impression.
Talking about men wanting to have "relationships" with girls carries the connotation that the men are much older, to the point of being creepy, or even that the girls are underage.