Feminization
Feminization is play in which someone who doesn't usually present or identify as feminine explores feminine expression — dressing, moving, and being styled as a woman. It may be self-directed or, often, done to a partner within a power dynamic. When it carries a humiliation or submissive edge (a dominant 'turning' a male sub into a girly, obedient figure), it's usually called sissification; feminization can also be purely affirming, sensual, or playful, with no degradation at all. It ranges from lingerie and makeup to a full adopted feminine persona. It overlaps with crossdressing, sissification, and transformation.
The appeals vary widely: the sensory pleasure of feminine clothing and makeup, the erotic charge of transformation, the submission of being 'turned' by a dominant, or the freedom and affirmation of exploring a different side of oneself. For some it's humiliation-hot; for others, gently euphoric.
A partner is dressed and styled as feminine — lingerie, dresses, makeup, wig, heels — and may adopt feminine mannerisms, a name, or a persona, often guided by a dominant. It can be a one-off scene or an ongoing dynamic, playful or intensely submissive.
Physically low-risk. The care is emotional: agree on the tone (affirming versus humiliating) beforehand, keep it consensual and judgment-free, respect privacy, and don't conflate the play with someone's gender identity. Aftercare helps if humiliation was involved.
Feminization and sissification overlap but differ in tone: 'sissification' typically adds humiliation and submission (being 'made' into a sissy), while feminization can be neutral or even tender — simply exploring or being adorned in femininity. As with crossdressing, enjoying it doesn't determine a person's gender identity or orientation.