Why does he want to do it so badly?

Alright,this guyfriend,who’s my age that I have,in my eyes,he is obsessed with sex!And yes,I know,he may be a typical hormone-infused teenage boy,but then again,he seems to scare me in a lot of ways,when it comes to that subject. Many months ago,from this year,he said that he wanted to have sex with me,but I swear,I thought he was kidding,but apparently not.To see if he liked me,or whatever,I told him to kiss me,and he made out with me,and this was in school,but then again,we don’t talk in school,but only on the computer. I go home.He said that he liked me,when I first asked him,on the computer,and then about 10 minutes later,he said he used me.That following weekend,he said that he wanted to have sex with me,again,and I told him that I thought he used me,and then he said he did like me,and then said that he wanted to be friends with benefits. No,I never had sex with him. Anyways,it seemed to go on.He would ALWAYS tell me when he was horny,and when he was “Jacking Off” and when he wanted to have sex.It slightly scared me.On the other hand,when he liked some girl,or when he had a girlfriend,he would stop telling me when he was horny.When he either had a girl,who didn’t like him back,or break up with him,he would turn around and say that he’s horny. Like,about two days ago,he said that he was horny,and that he was going to jack off.Seriously,to be honest with you,I want to know why he is like this to me.It is,then again,not scaring me as much as it used to,but then again,I want to know why he just wants to have sex with me.Why me?