Need help on this situation...

So,there's this guy which is 2 years younger than me,he's 15 and I'm 17.
It started 2 weeks ago,when I went to the cafe in the morning to be with my friends and they told me that this guy wanted to meet me and said I was cute.
So,that day,my friend who told me he wnated to meet said she talked with him and he said that he was 2 years younger than me,that he had no chance with me.She also said that if he didn't try he would never know if he had any chance with me and that I liked younger guys and he became all excited.
That same day when we went to the bar we usually go at lunch time,he seated at our table,next to me.Later this night I received a new number on my cell and it was him.He asked for my mail and I gave him and we talked on msn.So,next day one of the girls from his class which happens to be mine and his friend went up to me and I said that we talked the day before on msn and he was so into me.And so it seemed because till this Tuesday he started to go everyday to the bar we go at lunch time,sit at our table,then he would be with me at most of the class breaks and at noon,right after he got home from school,he would talk to me on msn till we go to bed.Even on weekends we would talk from about lunch time till late at night.
We started to have walks alone,after being a bit on the bar with my friends,we would leave and walk around town and then go back to the bar.And it started a week ago,on Monday.We were at that bar,he sitted next to me,and of course my friends meesing with both of us.One of them even started to write on her cell about me and gave him her cell so he could reply,without talking directly.She asked if he liked me and he said yes,then she told him to send me a text msg to cell phone with something like "I want your love",so that he could see my reaction on that minute...He said that it was too strong,that he would probably "get really dumped".So,my friend grabs his cell phone and asks him if she can send the msg,he agreed.When I received I was like surprised and happy,but didn't say anything.He was all red and my friend asked him if he was more calm now,and he said he wasn't.So my friend arranged some sort of scheme that made him go out,like "Someone is calling you from outside" and of course I went after him. We had a walk and he told me that he wasn't expecting this to happen so early,that he was expecting that it would go a bit slower.So I replied that we could go slower if he wanted.
And so we had our walk everyday at lunch time,and then returned to the bar.
At school after classes break we sometimes would have a walk around school by ourselves.As he seemed to be a little shy and I'm shy too we weren't always talking,but mostly enjoying each others company.
That week,Thursday,when I was with him and a few of my friends and I said I was hungry he offered to go with me to the school cafeteria to eat something.As I said I had no money left he offered again to go with me,and once we got there he said that I could eat whatever I wanted,making his money at my disposal.Of course, I thought it was really sweet from him.That same day,at morning, I apologised to him for the day before because I screwed up a little on msn,and told him that I was starting to like him and wouldn't want him to be fed up with me.Later after school on msn he asked if what I told him was true,which I replied that it was.
Next day, it all happened the same and I got really happy,because after he went away to have classes,he sent me a text mesg saying that he was in love with me,and he really liked me.We Talked again on msn at night ,and I told him that I really liked to go with him to see a movie and he said the same.On the weeked when he talked again he said that he has already talked with his brother and that he would bring him to my town so we could go to the cinema.I was really happy with that.
This Monday the same thing happened,he went to the bar and stayed with me,but after a long while he said that he had to go early to school and so he left.We even't had our walk around town like we normally do.
Later after school when I was waiting with a friend,for the bus. Another friend of mine and his friend said that he wanted to talk to me.So, when I saw him also waiting for the bus,I went up to him and asked what he wanted to talk,in which he replied "We talk tomorrow".And I stayed with him till his bus came and he left off,giving me to kisses in the cheek as usual.
I started to sense something was wrong,because he usually came to msn when he got home and that day he came later to msn.We talked and he asked if I liked him,and I said yes,and then he asked "What about if we started to make out".I asked if he liked me and he said "Yes,I do",and I was hoping with that question that he would ask me to date him.He asked me how many hours did I have for lunch and I took off as he wanted to make out the next day.I also asked him if my age bothered him and he said a bit, that he never dated anyone 2 years older than him,in which I replied "there's always a first time for everything".
So,the next day I talked to my friend and she seemed really surprised that he asked me to make out,because the day before they were "discussing" in class about me and him and he said he would talk to me about us dating.
So that day we make out,and after that we even took a walk by the school gym,hugged.So after that my friends asked if something happened between us and he said we made out.One of them asked if he liked, he said yes he liked very much, and she asked if he wanted to do it again in which he also said yes.
But after we made out we didn't talk anymore on msn,he didn't go to the cafe anymore to be with me.So I realised he deceived me and my friends too,all this time.But the funny thing is he continues to say hi at school,and I also do that,pretending everything's alright.He even went up to me later after school to give me 2 kisses in the cheek ,and then he back off a little but he ended to greet my friends too.And I forgot to mention that he blocked me on msn,before yesterday.
What I wanted is some opinions on this,and if you think I should teach him a lesson and what kind of lesson?And SOOO sorry for this long long and boring thread.

Don't be sorry for this thread, it was long, but definitely not boring. If it was boring I wouldn't have read it all. xD

My thought is, who in the hell does this guy think he is? I mean, I do see a couple possibilities. The first is what you said: he betrayed you, led you on just so he could make out with you. But, I guess there is that chance of it being that he's afraid? After taking that step, maybe he is afraid of going any further. It does seem very stupid and immature, yes, since he already made out with you (shouldn't that come after you start dating? I thought you asked someone on a date, not if you want to make out... or maybe I'm just naive?).

I think you should pull him out of the way and have a serious talk with this guy. Try to wring out the real reason why he did this. You never know- guys can act really, really strange sometimes. There's a good chance your intuition about him is correct, and if it is so, then it may be time to teach him a lesson. I guess the lesson would be to not to play with someone's feelings like that. I think just by letting out your feelings it would make him feel bad about what he did, if he had any conscience whatsoever. If it wasn't correct, if he just had cold feet all of a sudden... in that case, do what you think is right.

Thank you so much for your reply!
I've heard from a secure source that this isn't the 1st time he do this.There was a girl the told him that she liked him,then they had some kind of conversation about kisses and he asked to make out.And after that he left.But I don't know much more details besides this,but I'm trying to know more about this story.
Anyway,thanks again for the reply!Any more opinions/advice on this would be really helpful!