Such films continued to be produced but could only be distributed by underground channels. However, the tradition of bondage magazines continues in the form of art books of bondage photographs, published by mainstream publishers such as Taschen. For other scenes, particularly in established relationships, a safeword may be agreed to signify a warning rather than explicit withdrawal gay hentai of consent; and a few choose not to use a safeword at all. When all regions of the face are included, facial cum shots comprise approximately 62% of scenes where external ejaculation occurs. Rough sex pornography is similar to pornography featuring sadomasochism, gay twinks and typically features a Top who humiliates and/or degrades a Bottom while being physically violent towards them. In gay pornographic movies, actors who identify themselves as heterosexual, but who nevertheless perform explicit sexual acts with other males on film do not face the same stigmas as the mainstream acting counterparts and indeed can rise quickly to being featured actors. It may involve sexual attraction to women who are pregnant or appear pregnant, attraction to lactation, or attraction to particular stages of pregnancy such as impregnation or childbirth. Human urinal: An act common in the bondage sex community where a male or female slave will serve as a urinal for a dominant partner. It can be combined with fellatio and the woman may move her breasts up and down on the penis for an additional stimulation, usually before the man reaches orgasm. In straight pornography, intercourse is often followed by a facial, pearl necklace or other visible ejaculation. As with most forms of sexual activity, anal sex participants risk contracting sexually transmitted infections . Crying pornography that features participating actors crying. Some productions are noted for sophisticated porn milf and/or experimental storytelling and animation techniques. Ethnic pornography is a genre of pornography that features performers of specific ethnic groups, or depictions of interracial sexual activity.