So frustrated >:(

I honestly don't know what to do, I'm so scared to let him know how I feel... ever since I was little I always thought my cousin was soooo hot, as I got older maybe more than a few years ago I realized that he's so fucking sexy that I sometimes wish me and him could have sex. I know some people think thats wrong, thats why I had a hard time and still do to tell my cousin how I feel about him. Even worse now hes had the same gf for a year now so now I totally ca't tell him. It would be totally okay cuz he my adopted cousin so we aren't related, and to tell the truth I think he knew I liked him before but we were little cuz he once said its okay were not related so why don't you just tell me? He said it was okay, but again I said nothing. Now we are way older and I don't see him as much except some holidays but every time he just looks hotter and hotter, I instantly feel horny around him or just thinking about him it drives me crazy. I even have dreams about him like WTF?! I just can't help it..... I just think sex with him would feel soo good, I think i'd make him feel sooo good but I don't know how to go about this. I'm so frustrated >:(