Shaking my hand wayyy too hard, much harder than a normal firm handshake. Like, trying to hurt your hand kind of hard. And then not letting go after the handshake was over, just looking me in the eye, holding my hand hostage, while trying to squeeze as tight as he can. 

I just said something like "you're not my type" and he let go. I don't know why that worked, its just the first thing that popped into my head.