Voyeur or peeping Tom pornography is usually more staged with the subjects aware of the cameras, sometimes openly including this exhibitionist awareness. Sex experts have praised various techniques that the performer can use during fellatio to increase their partner pleasure. The interaction between tops and bottoms—where physical or mental control of the bottom is surrendered to the top—is sometimes known as power exchange, whether in the context of an encounter or a relationship. As with most forms of sexual activity, anal sex participants risk contracting sexually transmitted infections . Some couples use pornography at times for variety and to create a sexual interest or as part of foreplay. Anti-pornography psychologist Ana Bridges and colleagues conducted a content analysis of best-selling heterosexual pornographic videos showing that over 96% of all scenes concluded with a male performer ejaculating onto the body of his female partner. Sub-genres of Japanese porn Among the various sub-genres of Japanese pornography are the following: Lolicon ロリコン: This genre involves prepubescent and adolescent girls between the aged of 6-12. The legal status of masturbation has also varied through history and masturbation in public is illegal in most countries. Fisting involves the insertion of one partner entire videos porno gay hand into a vagina or the anal cavity. The Japanese sex industry uses the term Paizuri . Gang bang pornography is a type of pornography that depicts an individual engaging in physical sexual activity with multiple partners sequentially or at once. Instead, lesbian relationships have often been regarded as harmless and incomparable to heterosexual ones unless the participants attempted to assert privileges traditionally enjoyed by momsex men. Bukkake pornography usually depicts numerous men having sex with one woman, with multiple, usually 10 or more, men ejaculating on the female face. Though the term anal sex most commonly means penile-anal penetration, sources sometimes use the term anal intercourse to refer exclusively to penile-anal penetration, and anal sex to refer to any form of anal sexual activity, especially between pairings as opposed to anal masturbation.