ok I know what your going through and I don't want to say this to scare you but I am saying this because it has some simularities to what I experianced at 15.
I met my first boyf about 3 weeks before I turned 16, he was known around the village I lived in to be bad news but, one day I saw this side to him that, I really liked and from that moment started dating him, against the warnings that everyone told me at the time. I was with him for 6 months of my life and heres how it went!
As soon as I turned 16 he started pestering me 24/7 for sex even though, I wasn't ready for it. Now he was older than me by 3 years and a big guy, he knew this was my first relationship and from living in the same village and going to the same school, knew about my personality and that I had low self esteem. He used these things against me using mental mind games to get me to do things I didn't want to do, firstly you'd get the but I love you and want to show you it, and then if I didn't back down he'd get angry and insult me, often reducing me to tears to get what he wanted.
Regarding cheating he was terrible he'd chat to girls online right infront of me and he even called up my best friend and tried to get her to do stuff down the phone right in front of me, I once caught him coming out of a local pub with anouther girl! He'd tell me he wasn't doing anything and my low self confidence would make me believe it! It got to the point when he knew he had total control over me, he went with me and his friend into town and left me in the car on my own while he went into a adult store to meet a adult film star with whom, he had his pic taken and proudly showed me afterwards! It even got to the point where he'd go out on his own for nights on end and come back and show me pics of him with anouther girl!
Now your prob thinking why I stayed there with him, but I thought I could change him, I thought maybe he'll change for me, maybe he'll stop cheating but the truth is he never did or would! When I realised this I tried to get away but then he'd use my lack of confidence against me, he could be semi violent to me, he was into wrestling and would do the high flying moves onto me (16stone guy landing on 10stone girl) and I was scared of him. He'd even stalk me when I wasn't with him cause he thought i was cheating on him!!
In the end I plucked up the courage to leave him when I found some one else who treated me a lot differently, but the damage had been done, I went within myself, stopped eating, couldn't hold a realtionship because I was still terrified of him and scared of the same situation arising again. It's been 6 years since then and I still suffering from the affects of that relationship, I am now recieving counselling which, is helping a lot!
Now this is a extreame case of what rushing into a relationship can do but, it does happern. Again I just wanted to show anouther side to the story of what can occur in these situations.
I agree with what you said about liking someone even though they have done stupid things or do stupid things, cuz I wouldn't of gone into that realationship if I didn't.
The thing is you have to be realistic, there's a saying called your wearing rose tinted glasses, this means that because you have feelings for someone you'll try to mask out and forget about the bad points in that person. This is easily done with first relationships, your at an age where suddenly the opposite sex is more appealing, all your friends are in relationships and sometimes you can rush into it because you think the first guy that comes along is going to be the one and you forget to think it through.
It does seem like he is only after one thing otherwise, he wouldn't of cheated on you with someone else. If you entered a realtionship with him it could go two ways, you could give him sex and then once he's got what he wants, he'll break up with you or, he could try to force you into doing what you don't want to do and end up trying to control you buy either saying things that he thinks you want to hear or by attacking and insulting you both of which, he seems to of already done.
Trust me hun if your not ready don't do it! If he loved and respected you, he would wait until your ready (there is anouther way he can relieve his sexual tension without cheating on you!) If you go into a sexual relationship when you are not ready, you can end up regretting it for a long time and the hurt that you feel if he dumps you right after is painful. They always say that sex is more important to a women than a man don't let him take it away from you just, so he can add anouther number to his list!
I will be thinking of you, remember in the end the choice is yours to make do what you feel happy with! My PM box is always open if you wanted to talk
:hug1