The collar is next to the Ring of O is a common symbol of BDSM

In addition to these practices are known and the mutual rubbing of the genitals (tribadism), inserting the entire hand or forearm into a body cavity of the opponent (fisting), the sex between the breasts of a woman (Mammalverkehr), transport between the legs (leg movement ), the buttocks (buttocks-sex) or in the armpits (Italian). Specific forms of sexual intercourse include BDSM (if not the B-criterion of the DSM-IV-catalog is available), the fast sex (Quickie), the threesome (triplet) or in a group (Group Sex, Gang Bang). Without physical contact are the sexual and obscene talk (dirty talk, dirty talking, phone sex, cybersex), the observation of other people's sexuality (voyeurism), and the presentation of their own sexuality (exhibitionism) from.