What should I do?

Mk kinda long explanation but its kinda interesting and I really need advice so bear with me :) so this guy in one of my classes, let’s call him K, started TOTALLY flirting with me one day back in late December/early January ish. I had a boyfriend at the time, and K had just broken up with his girlfriend of 8 and a half months. I fell for him really bad and broke up with my boyfriend just so I could ask K to the upcoming sadies dance. to be on the safe side, I sent him a myspace message, saying “hey are you still going out with B? [his ex girlfriend].” which it said he read but never replied to. grr. anyway, a couple days after that, it was like a week before I was planing to ask him. my friend, during class, and I were passing notes and on a whim, we decided for her to pass him a note in which she ended up telling him that I liked him. he wrote “oh.. well I have a girlfriend” and she wrote “oh. well reply to myspace messages next time.” and he was like “what? well B has my password she probably deleted it.” so much to my embarassment, he had gotten back together with B AND she had gone on his profile, read the message, and deleted it. in the note though he also said that I was hecka chill and wrote down his number saying for my friend to give me his number, “if I wanted it.” I put it in my phone but still have never called or texted him.

so for the next month or so, he would message me or reply to bulletins I posted on myspace, and we would occassionally talk over myspace. I have a feeling B was still reading the messages though. what a beeeotch. haha okay sorry. also we kept TOTALLY flirting during class, though I tried not to as much cause it hurt me to see him with her while she treated him like shit and I knew I could treat him so much better. then they broke up again. he posted a sad bulletin and I replied and helped him deal with it. he said it was the last time, and he wasnt going to keep going out with a girl who kept pushing him away and hurting him. but then he said he still really liked her. I said that I thought he made the right choice and I assured him he would feel better soon. he said I made him feel a lot better. but then the next week they got back together! I was so pissed off. I posted a couple bulletin saying something along the lines of “I hate it when guys stay with girls who treat them badly” which he replied to and said “youre not talking about me are you?” and I was like “yeah.” and im pretty sure B read those. hahaha. but then I had to get a new myspace and I added him again, but we havent talked over myspace after that at all. =(

anyway that same cycle continued for a while.. pretty sure they broke up and got back together at least 6 times in the course of two and a half months. anyway, they just broke up again a couple days ago, and now they say they are just best friends. but I dont know if he still likes her or not. they still hang out all the time at school, and he left her a myspace photo comment today saying “favorite picture ever =) hottt”. but that could’ve been before they worked out that they were just going to be friends. I dont know! I have class with him two more times this week and I DONT KNOW WHAT TO DO. SHOULD I ASK HIM ABOUT IT, SHOULD I MAKE A MOVE, WHAT SHOULD I ACT LIKE/SAY!? I really like him and theres only a month left of school so I want to get something started before then, but I dont know how to act in such a way that will get him over B and onto me. HELP PLEASE =))