Bathroom porn is the kind of porn that involves a girl in a bathroom. The bathroom is the most important location for a bathroom porn video. There can't be bathroom sex scenes not set in the bathroom. There are some very important rules of the bathroom that make these scenes so hot. First off, water is usually involved in some capacity. You may see a horny girl taking a shower and soaping up her breasts or a busty babe who can't wait to take a bath so she can rub her pussy while covered in bubbles. Maybe she'll even have a rubber ducky toy to use as a makeshift vibrator. Anyway, these porn movies make creative use of water and shampoo and things of that nature. The hotness is just too much for words!
The second important part is that these movies are always set in a bathroom. This isn't a movie where someone is having sex in their own bathroom and then they go out to the kitchen and do it there. They are fucking each other's brains out in a public bathroom. The pleasure can be impressive, there may be some subdued moans and groans but the sounds are really loud!