Hey. .Why Do Guys Do This? Can You Help Me? I Need Advice?

My ex has a new g/f that he claims he loves. When they 1st got 2gether after our 1yr relationship he told me he will always luv me. He told me that she was trippin over somethin. Then he told me that he still luvs me as much as he did b4, he just dnt understand y he's n luv wit 2 girls. He wuld say hello & talk 2 me. Then him & his g/f broke up. We got back 2gether & he put our relationship on hold cause him & the girl got back 2gether. He said when school starts & they r not 2gether we will get back 2gether. Later I found out from his bestf that he told him about me **** her I only wanted her for . He knew we culdnt have cuz our parents were always at home. He neva even brought up , I always did. Is he playin the other girl? His bestf say he lost his virginity to the girl he's wit now. Will he want me back? Im so hurt. Its hard 2 get over this crap. Has this happened 2 anyone? I cant avoid him we go 2 the same school & hang wit almost the same friends. Please help me.