Boyfriends Friend Problem

Ha

Ok so don’t get this mixed up. My boyfriend and I have been together for 8 months now. When he first asked me out this girl was always trying to get with him. They’ve been on and off in a relationship until he got with me. A few days after we got together he kissed her. I didn’t find out until months after but I forgave him. Then one day at school he went into the hall with her to talk and she kissed him. He told me that day and I got mad but forgot about it. The girl has been trying to get him to break up with me from stupid little stuff. She even used the reason of me not changing my relationship status on Facebook to get him to leave me. She’s been butting into our relationship for a good few months now and she gives me the dirtiest looks. I told my boyfriend that he needs to drop her or I’m going to just leave. So he tried to but he ended up talking to her anyway. So now it’s a few months into the summer and this girl made up a story a few days ago about seeing me at her work with another guy. I was with my mom. My mom does not look like a teenage boy. So my boyfriend and I got past that and now he’s over here saying “she’s the only one who’s had my back and I want to keep her as a friend.” And I really don’t like that. He’s texting her a lot even when we are on the phone and he barely listens to me when hes texting. Then he asked me if he could hang out with her at the mall. I asked if any other friends were going and you already know the answer. They were going to go alone. I told him how uncomfortable that makes me since everything that has happened but he told me that it’s all in the past. I know she is no good and he is so set on how she changed but I talked to her recently and she has not. Now, what do I do? I don’t want to control him and who he can talk to but I’m okay with everyone else just not her. She’s the one person I can’t stand and he knows that. I told him we should compromise or something and he told me, “I’m not getting rid of her if that’s what you want.” So he’s being a real douche here. I’m very uncomfortable with their friendship but I don’t want to control him. And he was angry the last time I made him choose between me and her. I’m not sure what I should do.