The last chapter might of confused some people (as with one of the reviews have clearly been mistaken). Paul sleeps with girls not just to forget the pain of his mum being raped up but also for the pain of him getting beaten up. It's how he deals with it. Paul is known as a ladies man in a lot of fan fics and I want to keep that part going with him so it's not entirely different from all the stories. And it is one of the first big problems in Bella's and Paul's relationship. He sleeps with them to try and forget the pain, but it doesn't get rid of it- it's just like a drug to him. People have different ways of dealing with problems and for him this is the way he does it. He would also never have a committed relationship with them because he wouldn't know how to commit and hide a secret and he would be scared of being a burden to them and dragging them into the mess. Also he would be scared to become like his dad and he wouldn't be able to trust them. But with Bella since they share the same pain they can move past it with one another and understand how they feel and he can trust her. So therefore he just uses girls to forget his pain. Don't judge the poor guy