You do everything in your power to try and charm her and convince her she needs to be back with you.
all you can do is let them know how you feel, maybe start to talk to them more or even going out with them even if it means tagging along with him and his partner. and then if he likes you back he will let you know...
when she asks to go back to your place
Just be good friends (Girlfriend-boyfrind if you want) It is that simple. if he/she likes you but he/she doesn't know you like him/her. Just tell him/her.
Hit on him in front off her. Its hard to dislike somebody who you know likes you. And its hard to like somebody who has an eye for your partner.
If he likes you, then he won't have the other girlfriend anymore.
If you don't know if your girlfriend likes you then you need to get to know each other better because she should like you before you become girlfriend and boyfriend.....
make your girlfriend jealous
Ask her !
Well it souds like this guy has issues. I mean if he has a girlfriend then hoe do you know he likes another girl. And have you ever seen her. He could have a fake girlfriend to make other girls jealous. Guys have to feel superior.
As long as he has a girlfriend, say nothing.
then he must be cheating on you if he has a girlfriend? i mean if he likes you and has a gf then he must be cheating and wanting you?
bum her and if she likes it u know