Take the first step! Show him interest and hint of sympathy, make sure he notices and understands your signs. And you can give a number of reasons according to which you can conclude in favor of men. If in the park you got a Frisbee in the company of nice guys, don’t hide that you did it on purpose 🙂 Don’t answer all of them at once. Laugh from time to time, but without pretense, or walk past him into the bathroom. People don’t look alike.