Why is he acting so weird nowadays?

so heres my story....im 13 n hes 14..im in love with this guy for like 2 year...im good frnds with his cousin so i told her that i like him n also told her dont tell anybody!including "HIM"!bt she told him n i got pissed off cuz i thought that hes not gonna talk with me now....BUT he started giving me more attention after knowin this that i like him. and after some days he also asked for my number! i was hyped!and after some days HE texted me first...and then we were chatting for hours!he texted first everytime...n then i had to go out of country for 12 days n i dint tell him (i knw my bad!)n he texted me 2 times but i couldnt reply him as my cell was not on roaming. i think that time he got angry on me for not replying.bt when i was in in other country his birthday was there so first time i called him up and wished him and he sounded really good n sweet that day...but when i came back after 6 days from the phone call i texted him := wup n he replied=good and said=im happy cuz my new gf asked me out yesterday...why did he tell this to me even when he knew that ive got a crush on him?and after this ive texted him two times but he didnt reply...and i also texted him that = wats the reason why r u nt willling to talk to me bt again no reply....im fed up! why is he acting like this all of a sudden?should i ask him the reason when i meet him face to face? or just leave him and try to move on?n i dont know if the gf thing he told was a truth or not anyway guys im sorry for a long story bt i really need a good answer n im serious...thanx :)