Big butt porn celebrates large posteriors on amateurs and famous pornstars alike. The buttocks are rounded portions of the anatomy made up of a layer of fat covering the gluteus maximus and gluteus medius muscles. In many parts of the world they play a large role in sexual attraction and activity. Sex videos featuring big butts can involve any number of erotic activities such as squeezing, massaging, caressing, licking, fingering, using sex toys, pegging, and full-on intercourse.