I definitely prefer a guy to be taller than I am. I'm 5'3 so he should be at least 5'6 and most guys are, even a lot of young boys are taller than me. For porn if the guy is shorter he should at least be beefy and muscular or he's got to have a weapon. And honestly some spindly little man brandishing a gun to rape some big chic is not a turn on anyway