Why does he like that other girl?

Love is so fickle and no one can really define love. Beauty is in the eye of the beholder, so perhaps he sees something in her that intrigues him. It's hard to tell. Youth is fickle! Youth today can jump from one partner to another in a heartbeat and leave no reasoning or care of how they have hurt their ex. There are many young people out there that still care and stick to one partner. NEVER change who you are and hold your head up high and consider yourself lucky you got rid of this guy when you did. If you didn't then you wouldn't be free to meet that special guy that's going to come into your life in the future.