Am I a homewrecker?

I have a huge crush on a boy I go to school with. Me and him get along so great and I think about him all the time. I know we are extremely compatible and he always flirts with me. I could be waiting in line at a Taco Bell or Prom and thinking about how much fun I would be having if I was with him: He has been in a relationship for the past 8 months and I respect his relationship and girlfriend very much. Should I tell him or wait for them to breakup?