Serious Question about liking friends ex , need advice :/ ?

okay so to start im 15 almost 16, and my one friend...we'll call her alexa ,is always trying to find me a guy and stuff cause i've never had a boyfriend .. well this kid in my homeroom ( carter ) , and my other friend ( steph ) , dated for about a month back in march or april . they broke up , and steph still liked him. alexa & carter are good friends , and alexa .. told carter to start talking to me ,and hes like i always wanted to talk to her actually.. and yeah so anyway monday, starts texting me , we talk 24 7, so much in common. he starts talkign to me in homeroom in person ,and we get along good. well i told steph me and him are friends and yeah, she was like ok. then itold a few friends i might like him a little, of course somehow steph found out, and im like well what do i do. and shes like its fine just go for him. and then to others shes likehow could she blah blah blah. they only dated a month..and he said she was jealous of girlfriends he had before they even knew eachother?! idk what do you think i should do ? summers soon so steph wouldnt even found out if we dated or not.. like idk. hes so nice.