It starts with a finger in your ass while you're beating your meat because you're bored with normal sexual stimulation and a greedy bastard by nature. Next thing you know, you're getting piped left and right by any guy you can find. You justify this abnormal act against nature as a temporary quest for pleasure. You figure you need it bad (because you're greedy) and a girl isn't around that is willing, so you'll sacrifice your own dignity for something moist and tight to dip into. Before you know it, you'll be a raging homosexual.
Mind you, this horrifying transformation could have been avoided had you not been greedy and stuck with your best friend the hand.