What do i do? this guy really hurt me...?

okay so last night my guy friend called my ex boyfriend (we agreed to take a break but we still like each other). i was on the phone too and my friend told me not to talk. so, my friend says "weren't you and delilah in love?" and my ex goes no i pretended so i could get head from her. i was sooo extremely mad but i promised my friend i wouldn't let him know i heard what he said. after the phone call, i texted the guy and all my responses were angry and he asked why i was mad at him. i kept saying i wasn't, but it was obvious i was. i don't know what to do because to be honest, i never want to talk to him again. he cheated on me once and i forgave him because he got a lot of crap for it. he was my best friend for 3 years before finally getting up the nerve to ask me out, and when his best friend broke my heart, he was the only one there for me. he's honestly changed so much in the past year because of his friends, it hurts me how he doesn't even notice. by the way, we are both 15. i honestly (not to be mean or anything) hate him. i didn't even cry, i just wanted to hurt him badly, and i NEVER want to hurt people. i'm usually such a nice and good forgiving person! i don't understand what i should do; should i never talk to him again and not give him a reason because he doesn't deserve one? or should i give him a chance to explain? or should i just forget about it and start over fresh? also the other problem is that i have no idea if he was lying to my guy friend to seem cool like "no i didn't love her im too cool" or whatever. or maybe he's been lying to me everyday. i have no idea what to do. i'm sorry if this seems stupid or unimportant, but i was in love with this guy. he was that one guy that would never hurt me or use me or anything, and it finally hits me that he did. and the WORST part is that he's still friends with me. i would understand if he used me and never looked back, not caring about me, but it makes no sense for him to use me and then hide it and stay friends with me?! its cruel. i'm not sad, i'm just really confused and angry. PLEASE SOMEONE TELL ME WHAT I SHOULD DO PLEASE! ALL SUGGESTIONS APPRECIATED! :)