I want him :( But how can I get him?

There's a guy I became really close with last year.He's such an amazing friend now!He means a lot to me.He was there for me when I was having issues with one of his close friends who I was into at the time.We both liked each other but he was afraid of commitment and it turned awkward coz he was avoiding me and all.But anyway it was a tough time for me and this guy was there for me through it all.We chatted daily in school nd by phone.At the time,I was worried that maybe he liked me.At that time I didnt feel the same way but I kinda guessed he'd be the next guy I would fall for.We were talking once and he mentioned that his ex girlfriend had been talking to him a lot recently.He told me that they had a bad break up a few months ago because she cheated on him.I very foolishly and selfishly told him to go back to her.My worry was that maybe he would fall for me so if he was with her,he wouldnt want me as more than a pal.SHOCK ON ME!!!We had a trip to the coast as a cl over the December holidays and during that time,he and I spend loads of time together.I found myself really falling for him.One night when we were alone,I kissed him.It got pretty intense but he made sure I was comfortable the whole time.I asked him what about his ex and he basically told me not to worry.I admitted to him that I liked him.A few days after the trip,he sent me a text saying that his ex had asked for him back and he accepted and that he hoped we could still go on being the awesome close friends that we are.It hurt!And he knew it.Just before going back to school,the guy I liked before him cleared everything with me and we started talking again.I told the guy this and he was like 'the main reason I got back with my ex was because when we were had our trip,he seemed uneasy about us being around each other a lot.The last thing i wanted was for things to get awkward with me and him and you two' ..When we got back to school,seeing him was kinda hard.But we still remained close.Shockingly, I found out that he still liked me.He told three of my friends this,that apparently he cant do anything about it because he's in a relationship.I also found out from a few friends of his that his girl cheated on him numerous times when they first went out.Even with two of his close pals and he doesnt know it!!!They are against him going back to her.He is still determined to stay with her though; even though one of his pals also told me that the guy told him that he just went into the relationship without thinking about it and that he's torn between the two of us.Me and his girl. How can I get him??????????????? :( Please give me your advice!!!!! xxxxxxxx