A cultural trend in my country follows a particular course, with few variations. A marginalized minority or subculture produces it. It propagates via pop culture, especially music and film. Teenagers adopt and adapt it. A major motion picture blesses the trend. Older people who idolize teenagers take it up. The rougher edges of the trend have been removed at this point and it is a marketable commodity. It is now an ordinary and acceptable part of daily social life.
At this point, if the activity has any physical expression at all, it finally and permanently becomes a method of exercise.
The New Porn Culture of suburban middle-class America is no exception.