What do you think happened?

My daughter dated this guy for 3 years .. It seemed they got along quite well. He was over 4-5 times a week. One day he breaks up says he wants to spend more time with his friends (which my daughter never said he couldn't) and two weeks later dating (in a relationship) with a girl who has slepted with all his friends. Go figure. I am glad for her. He didn't have direction anyway. It is just weird.