Ex or Bestfriend?

I told you about Austin, right? and how we had a DTR a couple weeks ago?
-Well, he dated his "bestfriend" and broke up with her in December, right? He has complained to me before that he wasn't heartbroken because he lost his love, but that he was extremely sad and lonely because he lost his bestfriend. To me, your gf'/love should be your bestfriend, so I don't really differentiate between what he says. He was heart broken, in my opinion.

Well, back to my story, that "bestfriend" didn't talk to him for 5 months after breaking up, then she suddenly decided on Wednesday night to call him up and talk for 2 hours like nothing happened. He texted me about it and how excited he was that he "got [his] bestfriend back."

I decided to keep my mouth shut and ignore it cus it will probably pass over anyway.

I was willing to let it slide, to just let him figure out she isn't good for him on his own. But last night my sister had a melt down and I really needed to talk to someone. Around 5 or 6pm I texted him that I needed to vent and talk to someone and asked if I could come over. He said "hahah, I guess," clearly not grasping how serious I was. So I said, "yes? I can come over then?" He never replied.

I texted him a few hours later to ask what he was up to and he replied that he was at Alyssa's house (his "bestfriend") baking cookies.

I told him that I needed to talk to him. When he finally called me at 1am, I told him that I know I have no right to be jealous, since he and I are not dating, but that we did promise to explore whether we wanted to court. He says they are just friends, but he doesn't get it. He doesn't understand that it really is impossible for a girl and a guy (who have dated and gone as far as he went with her) to completely be "just friends."

Even if he CAN be just friends with her, it is not appropriate or fair to me. It is also just not smart. No matter how good of friends they were. I don't care. He needs to respect me if he is going to be serious about thinking about courting.

I think I am gonna cut him off. I don't want to. But I also can't be his "back pocket girl", especially not for a 17 year old. I need to draw a line and have boundaries; I also need to respect myself. Continuing to hang out with him when he hangs out with his ex/best friend does not show self-respect. One could argue that I don't trust him, but I don't think he should be putting me in this specific position that "forces" trust.