I have a crush on my half uncle...help?

I'm 17 and my half uncle just turned 19. He is ny mom's half brother. He js a really great guy, and attractive too. I feel really weird when I think about him yet I want to act on my thoughts. He kind of flirts with me too. Should I subtley try to tell him? I'd fight for it against our families because I do not see too big of a problem as long as we do not have kids. Does anyone else think it is horribly wrong or anything? I mean a relationship is a bond between two people and if it did work, and we wanted kids, we could adopt. I mean I see people marry their brothers and sisters or first cousins. What should I do?