A bisexual threesome may involve a man having sex with a man and a woman, the woman having sex with a man and a woman, or all three having sex with each other. Activities range from a spontaneous smack on bare buttocks during a sexual activity, to occasional sexual roleplay, such as ageplay, to domestic discipline and may involve the use of a hand or the use of a variety of spanking implements, such as a spanking paddle or cane. Production of such films was profitable, and a number of producers specialised in their momporn production. Swinging can take place in various contexts, ranging from a spontaneous sexual activity at an informal social gathering of friends to a regular social gathering in a sex club or residence. Rubber pornography involves rubber, latex, and similar materials. A 2009 study found that heterosexual male fat admirers preferred females that were clinically overweight and rated both overweight and obese women more positively than slighter individuals. The term has also applied to other professions and even companies trying to appeal to a gay demographic. A lesbian is a female homosexual; a female who experiences romantic love hentai movies or sexual attraction to other females. The precise definition of roles and self-identification is a common subject of debate, reflection, and discussion within the community. The activity is done by itself or as a part of or prelude to other activities which many times involve sex. The genre is popular enough in Japan that it is even the subject of gay fuck parody. Many of these activities might be based on rape. Some people get sexual pleasure by inserting objects, such as urethral sounds, into the urethra , a practice known as urethral play or sounding. As well as traditional attraction, the topic also incorporates feederism and gaining, where sexual gratification is obtained via the process of gaining body fat. The warm sensation felt when urine trickles on the body seems to give very relaxing and pleasurable feelings to the person. By comparison, gonzo pornography puts the camera right into the action, often with one or more of the participants both filming and performing sexual acts, without the usual separation between camera and performers seen in conventional porn and cinema.