Do I let them have sex? Is this okay?

I can't believe I'm asking this but here it goes...

I recently went through a break up (my first very serious relationship) we remained friends with optimism that things might work out in the future. We both exchanged several harsh words during the break up however, several weeks afterwards I decided to let him have it again. I was not kind and got pretty out of control.

While name calling is never okay, I firmly believe that it's easy for someone to lose their temper but it takes strength of character and courage to apologize and rebuild trust and I have continued to apologize and make up for saying things I did not mean (which we both did plenty of).

Plot thickens: I decided I wanted to continue our relationship. Not only are we great friends who had a great relationship before it turned rocky but I also see a very bright future for us and we still love each other a lot.

Shortly before we broke up I attended a party with him where a woman (that's a stretch to call her one) very obviously made attempts towards him in front of myself and the man she was seeing at the time (his very good friend). Needless to say it made me really uncomfortable and angry. Apparently she continued her pursuit of him after his friend broke it off (wonder why!?::cough:: slut ::cough::)

It wasn't until after I told him I no longer wanted to speak to him in my moments of fury (which lasted about a week) that he started talking with her. Anyways, now they're sleeping together but he assures me he has no feelings for her, they're just **** buddies. He's just single and she's spread low and wide, clearly.

I trust him implicitly because he's never given me a reason not to. He is a great guy. I came back into the picture swinging and knocked things off kilter, that I understand... However, he agrees that one day we will be together again just not now. "Maybe soon, maybe next Christmas" but I need more than that and if I were "the one" wouldn't he want to be with me? Do I sit by idly while he casually sleeps with this opportunist friend hopper (who will surely keep hopping) or do I walk. Do I even have the grounds to say "you either want me or you don't?"

Ugh... I feel better. Kind of. Advice much appreciated.