HELPPPP PLZZZ!!! whats wrongg with this boyy?? whys he being like this?? jealouss??

ok well iv'e like this boy for 2 years now! we went out 3 times but his mate told me that he was only going out with me for a joke! we havnt talked for a year now! =[ and today we had an embly and people were performing and my mate she was dancing again and shes really good then when the embly ended i saw her with her arm around him and her arm around his twin,,his twin put his arms around her too but the other twin that i like didnt, i got really jealous :( because i really like dancing too but i never end up doing it for some reason,,and in embly he kept looking back at me and keeps looking at me! this girl fancied him too but he never went out with her for a joke,everyone hated that girl because she was a liar but he never went out with her for a joke,but he useto call her names and that! whats going on? what can i do/ im too shy to talk to him and he wont talk to nme he only looks at me :(but like him but,i hate him for what hes done but i try and forget him but i cant,,