2 random hot guys came up to me and my friend and ignored my friend but flirted with me?

well my friend and i were sitting in the park on a hill and we saw these 2 really good looking guys :) they kept looking up so we and my friend were laughing sooooo much and then we saw them coming for us and we were like AHHHHHH! so they sat down beside us like they knew us really well and started talking but they completely ignored my friend ;L i felt so bad so tried to bring her into the conversation but they didnt take any notice. so one was like to me hey lets go get an ice cream so we walked to get one and he was like your eyes are sooo pretty and i just smiled and was like thanks :)he got my phone number and stuff, so we went back and chatted for a while and then my friend and i had to had to leave, she was really upset and was like boys never find me attractive around you but i dont think its the case because i think shes beautiful, i told her it was coz i was a bit more confident. anyways shes really mad at me now and was like you shouldnt even go out with that guy, hes prob doesnt even like you and is just desperate which i thought was really mean of her. i really like him and i know i dont know him too well but we met up again privately just as friends and hes soooo lovely :D hes slightly older than me, im 13 and hes 15, but what do i do? do i drop him because i think my friends a bit jealous or do i go out with him and not care what she thinks? pleaseeee help!!!!!!