A loose girl or woman. A slut. A female who is not very choosy about who is shooting semen into her. Sperm toilets are commonly found in nightclubs, bars, concerts, St. Patrick's Day parades, colleges and universities.
Sperm toilets make excellent temporary girlfriends because they all swallow.

When you eat dirt for the first time and leave your family to build a shack in the woods

A "sperm toilet" normally refers to a female in her teens or twenties, or possibly even her thirties, who has sex with many partners. She is promiscuous, and allows her sex partners to ejaculate into her vagina, mouth, and even into her anus. She can also be classified as a receptacle.