Will he break her heart?

My ex boyfriend is dating my (or so I thought) best friend. She turned her back on me, uming she was better than me, but in fact, I knew her weak points, I always cheered her up, and I always made her laugh hysterically. Now she hates me, why? I dont know. But now she is dating this guy I fell head over heals for. And he stomped all over my heart. I am sure my old best friend finds herself superior to me, but shes not. He mentally abused me, threatening to break up with me for little things, ignoring me, being mean. Will he do that to her? He also abused his ex of 3 years physically. I hope he hurts her, I just do, she deserves it.. do you think he will? I heard a while back that he yelled at her for hanging out with a friend...and they were just DATING.