4. How To Train Your Dragon
Plot: A hapless young Viking who aspires to hunt dragons becomes the unlikely friend of a young dragon himself, and learns there may be more to the creatures than he assumed.
Porno Plot: This one immediately lends itself to having a porno title when you allow "dragon" to refer to more than just a mythological creature. There could be male and female versions of this one. Perhaps it would be about a religious man who finally opens himself up to his inner sexual nature and he would begin finding women to help him train his "dragon." By the way, if you're wondering why I'm bothering to come up with plots for these porno titles, then feel safe in knowing that I am wondering the same exact thing...