When you feel that had on the back of your neck, you know you're going to have to go all the way down to the balls, and you have to begin thinking about how not to gag on it.
He may have started out straight, but after he sucked all those beautiful cocks and swallowed all that cum he's just gonna look for more cock to suck because you guys know that after you suck your first cock you're hooked for life.