The first explicit pegging scene is believed to have been in the 1975 pornographic film The Opening of Misty Beethoven. Some are aroused from wetting their diapers, others like messing their diapers. This is commonly called double vaginal penetration or double stuffing. Urolagnia is a form of salirophilia in which sexual excitement is associated with the sight or thought of urine or urination. Content featuring male bisexuality has been a growing trend since the advent of internet pornography. Diaper fetishism is totally independent from pedophilia as the wearer derives pleasure only from the diaper and/or use of it. Bondage pornography specializes in the depiction of sexual bondage or BDSM activities as photographs, stories, movies, or drawings. The activity is done by itself or as a part of or prelude to other activities which many times involve sex. Sadism describes sexual pleasure derived by inflicting pain, degradation, humiliation on another person or causing another person to suffer. The industry generally refers to such films as adult films, hentai porn which is part of adult entertainment. It is typically animated pornography, as the legal age to be featured in a pornographic film in Japan is 18. Types of anal sex can also milf fuck be a part of lesbian sexual practices. Since mammary intercourse is a non-penetrative sex act, the risk of passing a sexually transmitted infection that requires direct contact hot gay sex between the mucous membranes and pre-ejaculate or semen is greatly reduced. The porn industry and viewing public were shocked by the then-taboo spectacle of a white woman having sex with a black man. Such ejaculation can be done by mammary intercourse, or masturbation over the other person, or result from the withdrawal of the penis from a partner mouth as he is ejaculating following fellatio, irrumatio, or intercourse. If dramatic skills are not involved, a performer in a porn film may also be called a model. Mutual masturbation, mutual manual stimulation of the genitals between partners, can be a substitute for sexual penetration.