He would rather spend his time with her than me?

He split up with me four months ago and got with her a few weeks later and then after about two months we started talkin again and he said to me that he wanted to get back with me and be with me but he was scared history might repeat itself, he eventually left her anyway and said that she was just a rebound relationship, now that he is basically livin back with me again he is still spendin time with her and he say's that he can do what he wants as he is single after all, we were together on and off for five years and we have got a two and a half year old together, he say's that he still loves me and wants to be with me but she is always buyin him clothes and givin him money and she is basically lettin him use her, I just don't know what to do any more, I have tried to move on with my life but I still end up wantin him and missin him so much, she is ten years older than him and she has four kids, he say's that he has no feelings there for her and it was only ever between them but I just feel like she is in the way of me havin my family back again