Important thing is did he say that he liked her back?

Think this boy needs his ego stroked and that is why he is telling you this and being very unkind by telling you, very selfish and mean to cause you anxiety and pain. You deserve better treatment than this and you should tell him that.

If he is thinking of leaving you for this girl you need to know. Be strong in approaching him and don't let him see your anxiety. If he says something like "I don't know" you should make the decision as to whether this person is really worthy of you. People like this are not really relationship material because they are players,

Good luck with this,

Rhiannon