He said I wanted to talk to you, but I had to restrain myself. What does he mean?

Because he already has a girlfriend, you belong to a third party now. He must have feelings for that girl, otherwise he wouldn't be with him. Because of your appearance, he may have a burden, he may really like you, but he will like that woman better, because they should not simply fall in love, and may have talked about marriage. Under such circumstances, his choice is very painful. Of course, if you do this, he will be very painful. It's better to be rational when dealing with feelings. Better talk to him about who he really wants to be with. Of course, if he really wants to be with you and barely stays with that, everyone will not be happy. If he says give him some time, I advise you to quit, and you will not be happy together in the future.