We were kissing and

So my boyfriend and I were home alone for a couple of hours. He helped me do chores, blah blah blah, so I add to get some information off my brother's computer and a porno popped up. I kept apologizing to him because I didn't know it was going to be on there. So later on in the day, we  ended up on the couch kissing, but things got heated, he moved me into his lap, grabbed my ass, and started moving my hips back and forth on him. The first couple of times I tried to get up he didn't let me get off of him, until I started crying is when he let me go. I was so mad at him for doing that.   Then a month later we were kissing again(I was cautious) and he jammed his tongue into my mouth, got in top of me, and started grinding on me. It felt good but I wanted him to stop to i pushed him off me. He said "Come on babe" then got back on top of me and pinned my arms down. This time we were at his house and his family was upstairs we were in the basement(how stupid of me). So I cried and cried, he didn't get off of me. I had to strength to knee him in his balls and went home. I haven't spoken to him ever since it happened and he keeps texting and calling me. I don't know why he keeps trying to have sex with me. Help?