Forced feminization, or sissification, refers generally to the feminization of a person who identifies as male. The term was originally used in the context of BDSM to refer to the forced feminization or gender reassignment of a male-identifying submissive. As with any activity, each party has to give their enthusiastic consent and have the right to withdraw or revoke the consent at any time, for any reason.
Through forced femization, the submissive becomes more effeminate and exhibits feminine behaviors. The dominant partner takes control of this process. The submissive is "forced" into cross-dressing and gender reassignment. They may get asked to try traditionally feminine activities, such as performing housework or applying makeup. They may transform their bodies by tucking their penis between their legs, removing their body hair, or wearing prosthetic breasts. They may also adopt a feminine voice and name.
As forced feminization reinforces the dominant and submissive roles of a BDSM couple, the process can be very sexually arousing. Sexual play can be a component of sissification. For example, rather than having penis-in-vagina sex, a dominant may use a strap-on to penetrate their partner anally. This puts the submissive in a more "feminine" sexual role. The dominant may also stop the submissive from touching their penis for sexual gratification.
The terms sissification and forced feminization have also evolved to refer to the loss of hyper-masculinity in society. Generally, the term "sissy" refers to a male-identifying person that does not conform to traditional gender roles. Sissy is thought of as the male equivalent of a tomboy although it traditionally has more offensive connotations. Strength and heroism seemed masculine while being a sissy was weak. However, as modern society has shone a light on toxic masculinity, some male-identifying people aim to distance themselves from traditionally masculine traits and become sissies.
Part of the appeal of forced feminization may come from the pressure society puts on men to be traditionally "masculine." A man who is drawn to things labelled "feminine" may feel that he cannot indulge that part of himself. Having someone "force" him to do so provides an outlet for those feelings. In this scenario, it is not the man's "fault" that he acted in a feminine manner. This helps relieve him of possible guilt or angst.
Sissification and forced feminization should not be confused with male-to-female transition or feminine presentation in nonbinary people. While these people may present or act in a more feminine way when they previously presented or acted in a more masculine way, they lead this change. It is not a result of the influence of a more dominant person or society as sissification is. People also undergo this type of change to align their gender presentation with their gender identity. Also unlike sissification, transition is not done for the purpose of sexual gratification, or for the gratification of others, although the confidence it brings may increase sexual satisfaction. Although forced feminization is distinct from transexual identity, the practice may resonate with closeted trans people looking for safer ways to try on a feminine identity.
Forced feminization is a commonly requested fantasy among dominatrixes and other sex workers.