This new girl is not pretty at all.
Most Helpful Guy
Have you ever heard of a "rebound relationship"? Many people will break up, and then get together with the first person to come along just to be with someone again. Rebound relationships rarely last, because they usually aren't built on a real connection.
Anyway, another thing you need to learn about relationships is that, once they are over, you need to NOT CARE what your ex does. He is your EX, which means he is free to do whatever, including make huge mistakes. Don't let your ex's affect you.
Most Helpful Girl
Maybe he's grieving and he's just getting some side chick to help get over you. Or maybe he didn't really care about you (I'm sorry I'm not trying to be mean just saying)