Take him back?

Maddie
This kid has been my best friend and boyfriend for a year now. Both of us lost our virginities to one another, we both respect sex and we never based our relationship on it. Well here is what has been going on recently, there is this girl he liked last year, she's absolutely stunning but she's a complete and utter WHORE. She cheats on her poor boyfriend all the time and she seems to be friends with mine. I wasn't cool with that obviously. Yet I never said anything to her, all I did was tell him to avoid her and to stop all this chilish stuff. A few months later she starts pulling up pictures of me at cosmetology school (I go there as well, she's in the afternoon class and I'm in the morning) and she starts talking bad about me and calling me ugly and etc!? I never talked to her and I was very mad so I texted her and threated to beat her up *my bad* then the crazy girl tried to get me kicked out of cosmetology for harassment!? This isn't even close to the end. So on the junior class trip to an amusement park (I couldn't go cause I'm a sophomore). He walked around with her throughout the whole thing! He claims to not talk to her and that she talked to his friend the whole time and all they did was walk together but still! So I broke up with him for like a day, then got together again shortly after. Okay now I decided to get a free texting app on my phone and try to be the girl, I said "oh my phone broke I dropped it in a creek etc, his response was "oh that's why you don't take it skinny dipping" he also admitted to thinking I'm crazy for not wanting them to be friends and that it was okay to text her, also said that they are friends(he lied to me cause he said they weren't and that he hated her). I don't think he should engage in conversation with her in respect for me, I know he would never cheat on me, he just frustrated me so much, I'm not the kind to be anti friends with girls, but she's a slut and I can't do this. I broke up with him and he cried so hard, were so close and it was hard to see him like that so I took him back again but I feel like I don't trust him anymore, I feel like he'd text any girl that would text him, that he wouldn't tell me and stuff could go down. I don't know if I should of taken him back