Diverse uses of ass

The anus is a corrugated circle that has a well-defined physiological function. But the ass is framed between the buttocks and the vaginal vulva, which makes it an object of sexual desire. It is often used as a source of erotic pleasure, which sometimes implies that, in order for the rectum to be occupied by the cock, the anal sphincter must be painfully dilated. To avoid this, some people use dilating objects, before the ass hole is penetrated by a real cock.