Is my supervisor at work flirting with me?

My supervisor at work is openly gay and I have started to develop a crush on him (I am gay too, he doesn't know that though). He has been doing some things that might indicate that he's flirting. While he is very rude and condescending to me and everyone else at times, I noticed that whenever I say hello to him and shake his hand, he always demands that I grip his hand harder and shake it harder. He doesn't do this with any of my other male coworkers. Does this mean anything? Also, should I tell him that I'm gay?