Basically, just the process of putting something large into your genitals. Be that dildos, plugs or any other kind of sex toys, or even a large penis / some other kind of object.
Nineteen Days Too Long by Lady Katherine
Nineteen Days Too Long by Lady Katherine (Archive Link) This lovely little latex short-story by Lady Katherine follows the female main character finally getting out of her chastity belt in which she had been locked-in for the past nineteen days. Being highly sensitive and sexually frustrated, she quickly freshens herself up and begins dressing in her multiple layers of latex and leather, to finally have her long-deserved fun… ...