Well wait for him to break up with his girlfriend but don't be the one to break it up.
If you like a guy and he has a girlfriend then you should back off and only try and be his friend.
If the boy has a girlfriend, find a guy that doesn't have a girlfriend.
wait
...
He has a girlfriend. So you butt out. It's not complicated.
you use his girlfriend like a ladder and jump over him
Well, its ok for them to hang out. If you trust her, then yes, if not then go with her. Like a double date.
You shouldn't flirt with him if he has a girlfriend.
Spy on him! A wife caught a guy redhanded giving nude photos of himself to his girlfriend.
You simply ask him.
you can tell him, or his girlfriend if you are friends with her
Yes.