in love with a cheater

So, i have this friend... we've been fucking for about 6 months, and somewhere along the way he got a girlfriend but didn't told me until he was like a month into that relationship, we didn't stopped fucking. Recently i've felt different with him, even the way we fuck has changed, everything is reciprocate, sometimes slow and very passionate, we really loose everything in the moment, we are just two bodies feeling and loving. It really feels more intimate and we feel closer, we talk more. Im just so confused, i don't know what to do or what to feel or what to say, and i dont know if he feels the same... i am afraid to ask him forfear of losing him...