Please can somebody help me i just don't know what to do

He's my best friend in the world. Were like an old married couple we've dated twice and broke up two months ago. we've been flirting recently and i started to fancy him again. My best friend told him that i fancy him while we were all sitting together as a group . He still flirts with me yet he doesn't want to be my boyfriend. After two attempts i've really had enough now, but i can't handle all the flirting! what should i do? if i tell him how i feel about it then our friendship could get damadged even more than it is right now. my best friend says maybe we could just be the two that flirt, but i've already hurt after all of this and my best friends stupid actions i just need to know what to say to him?