HELP ME WITH MY GUY PROBLEM?

ok lately ive been having the time of my life this summer hanging out with ppl and i find this guy who thought was the nicest guy ever, and soooo cute, and im 15 and not the best looking, but anyways he said that he likes me a lot but he has a gf. i said ok but i still flirted with him a lot and i held his hand a lot,then just today i herd form his bestest freind he called me a fat a s s ********* and a , and thta he was just playin me to try to get in my pants and idk if i should believe thta, i mena i do but idk,i just dont what i should do now what should i say to him?or should i just forget him and move on?