Ok, what makes your dick hard without fail everytime?
Hmm.... to be honest Miss Mandy, I'm a really aural guy. Hearing the right words in the right voice can have as strong or stronger effect than a powerful visual. In my porn I quite like POV where the girl talks to the camera before she starts stroking or sucking, or those JOI videos where the talking is done directly to me, the masturbating viewer. I like phone, and nothing makes the little man stand up quicker than being asked "is your cock nice and hard for me" or "are you stroking it" for instance. It makes the ending hotter too if certain words come out, including some obvious phrases and a few less obvious ones that cater to my sub side, which I certainly won't reveal here. I've probably got a top ten things I like to hear, either in my porn or a real life liason. Probably helps that hearing some of these specific phrases stirs memories of when I've heard them during my own sexual encounters.
Well, you did ask. :o