advice please

hey guys!! so I have a really close guy friend that I became closer to in the beginning of the school year. He is an ex of a friend of mine but shortly after they broke up a year long relationship she encouraged me to befriend him because she thought we'd click. We talk about everything together and I really enjoy his company. The friend is not too bothered by us being friends but at times she does say that she misses him, they are not on good terms anymore. Also the boy has an eye on a girl who he can't date until he leaves high school because his parents don't like her.

Recently he and I have been feeling sexual tension and I am tempted to make a move on him. I trust him so much and I feel safe with him but I'm scared our friendship would be ruined if we hooked up. I know he feels it too, he'll often compliment by boobs, he calls be beautiful, and we r constantly touching whether it is our legs or shoulders. We do have a fairly flirtatious relationship but I'm scared that hooking up would change our dynamic. He also plans on being with this other girl when he gets out of high school but he rarely sees her and the only relationship they have is over text. Sometimes I think he idealizes and does not truly know her. But what do I do?? Should we become fwbs, hook up once, or just keep the annoying sexual tension untouched?

Thanks girls ♥️