I dont know what to do in this situation!?

My friend is asking me for advice on her problems with guys right now and I'm stuck. She really likes this guy who is completley gorgeous and has an amazing personality. He doesn't know that though - he thinks they're just friends, so he tells her everything. He told her today that he is cheating on his girlfriend with a skank because he wants her in bed. She got really hurt by this information because he was telling this to a girl who he thought was just his friend, but who was - in fact, falling for him. She doesn't know if she should give up on him and move on so that she doesn't get herself involved in guys like that and so she doesn't get hurt, or if she should still like him. I told her to move on, but that's really hard considering she's liked him for so long.