My boy friend still hangs out with his ex

I'm 23-yrs-old and I met this guy recently who is also in his late twenties. He met me when his 6 months relationship ended with his ex and since then we've been dating. We both resolved to abstain from sex until I make up my mind, but He enlightens me on other ways to satisfy a man without sex. He was out with his ex on his birthday, though He claims he wasn't aware of the arrangements.

We've been having issues since then because it seems his ex wants to get back and He's giving her the attention too.
He claims her people knows about their relationship, He has apologized to me but He keeps mentioning I'm rushing things with him and we should take it slow. He's a media person, He claims He's hardly changed. I chat him up first, I do the calling and all. I'm worried because he flares up whenever I mention him meeting my peeps. I'm confused.