Preggo pornography features pregnant performers and may include erotic lactation as a fetish. The full-weight body-pressure, moisture, sex odors and darkness can be perceived as powerful sexual attractions or compulsions. Group sex most commonly takes place in a private sex party or semi-public swinger gathering, but may also take place at massage parlors or brothels or, in some jurisdictions, at purpose-built locations such as sex clubs. It is also known colloquially as gushing or squirting, although these are considered to be different phenomena in some research publications. It has also been recommended as a form of foreplay or safer sex. Two women tapegagged and cuffed to iron bars Bondage and Discipline are two aspects of BDSM momporn that do not seem to relate to each other because of the type of activities involved, but they have conceptual similarities, and that is why they appear jointly. The niche popularity grew significantly in the latter half of the first decade of the 2000s. Urolagnia is a form of salirophilia in which sexual excitement is associated with the sight or thought of urine or urination. It is sometimes combined with BDSM features. The naked appearance of actress Demi Moore in the advanced stage of pregnancy on the cover of Vanity Fair magazine in 1991 marked the beginning of a period which has since seen pregnancy presented by celebrities as a glamorous state of living, while also creating a market for photographers to produce images of pregnant mothers, and for fashion stylists to introduce pregnancy styling to their business. Some men also enjoy anal stimulation, with fingers or otherwise, without any prostate stimulation. Irrespective of the legal or social view of pornography, it has been used in a number of contexts. Hamedori is a genre of Japanese pornography in which a male adult video actor or director serves as hentai movies the camera operator. Both forms of pornography generally contains nudity. They may regard it as an enhancing element of their sex lives or as their primary form of sexual activity.