There are a lot of different sexual fantasy situations that are played out in adult videos that appeal to the masses. Most of the fantasies seen in Porn movies center around something not ethically acceptable in the real world. There is a forbidden element to relationships portrayed and the feature subjects like those between a boss and worker or a teacher and student. The teacher and student fantasy is actually an extremely popular one. This is always written as young college coeds students not high school students even though the actors are dressed in a manner that portrays them as being much younger than they are.
Typically they are in short plaid shirts, white shirts and white knee highs with patent leather mary jane shoes. Sometimes they are wearing white panties. Never thongs. The fans of these movies want the actresses to look and act as innocent as possible so the sex acts will get them hard. This which adds another layer to the element of the forbidden. Any sort of forbidden relationship is played out in Porn skits and films and often it goes that the more forbidden the better. Incest has long been a staple feature in the movies with movies like Lolita and Pretty Baby. But in porn incest themes will land a producer in jail. People have had their computers taken and lives ruined for accidentely being on an incest site.
So no matter what Hollywood is doing porn companies will always stay clear of that topic. The key in that business is to spot trends before they arrive so that a film maker can be in on the ground floor before anyone else and thus make a lot more success for themselves. If they can do this then they will have secured themselves a firm spot on top of the food chain. Those that don’t make it or stay with old and out dated material will eventually fall to wayside.