Generally speaking, younger guys (teens, early 20's), guys enjoy having sex because it eases a sexual hunger they have. They might like the girl they are having sex with - hard to say. Sometimes, it's more to scratch an itch than to nurture a relationship.
Young guys hormones are all about sex and thats about it. You will find a few diamonds in the rough.
"Trousered apes" do so.
Men of "real sensibilities" realize that if two people's hearts and minds are not involved as well, such interactions tend to be much less than satisfying.
So they tend to avoid such occasions.
Men (and especially boys) do much of their thinking below the waist. Like women, some discriminate, some do not.
As a rule of thumb you can assume that if it's available he's going to go for it. Gratification trumps romance every time.
Much like drugs just say NO!!!!!
Don't wait until you wished you had listened.