Tucking
The practice of concealing the testicles (and sometimes the penis) so the crotch appears smooth or flat. Tucking is common among transfeminine and non-binary people to reduce genital dysphoria or create a more feminine silhouette.
Tucking can be done with a gaff (purpose-made undergarment), medical-grade tape designed for skin, or tight-fitting underwear. It should never be done with household tape or cause pain, numbness, or difficulty urinating. Regular breaks are essential — prolonged tucking can lead to skin irritation, infection, or hernia risk.
Tucking is completely optional. No one is required to tuck to be a "valid" trans woman, and comfort always comes first. For many people, hormone therapy reduces testicular size and makes tucking easier.