do i like him... again?

so i am going into my senior year of high school but just a few months ago was around the time of prom. i made arrangements with one of my best friends (we’ll call him mark) to be my ride (kinda like he was my date without actually sayin he was my date). just a couple weeks prior to that the vibe between us changed. it wasn’t like a bad change either. anyways after prom people start talking saying “ohhhhh they’re talking now. they’re so cute” yada yada yada. i started developing feelings for him you could say. but i wasn’t 100% sure on how i felt about him because at the end of the day, he’s still one of my best friends. now cue in this one girl that i’m sort of friends with (we can call her liz). i’ve known her since kindergarten and everything between us was secretly a competition. if i had something she had to have it. from clothes hair shoes to my friend group and even the boys i thought were cute. and it got annoying. so when she heard that me and mark were possibly talking (which tbh i didn’t know if we were or not), she had to jump on it. and then boom, they’re a thing but he never cuffed her. whenever liz talked about mark or people talked about them i got this weird feeling deep down. like the feelings i had for him were always still there although i was confused. they continued to talk for about two months until recently. mark and i, still being the close friends that we are, were on the phone one night when he told me he didn’t want to continue talking to her. he said he didn’t like the vibe they had, she was telling people their business (after he told her he didn’t want that because he’s a very private person) and overall he was just tired of talking to her. eventually they got in it hand ended things. ever since that night he called me telling me he didn’t wanna continue with her, we talk every single night. whether he comes back from work or practice or he’s playing with his boys we’re always on the phone. and idk why but the feelings that i always had are like resurfacing. i know it’s wrong of me to feel this way about someone i’m very very close to and to feel this way about mark especially after he and liz were done. i’m just confused. i don’t want my feelings to ruin a friendship