Dirty Mom

The mother of all the "Dirty" names. The Dirty Mom is reserved for only the select few who posses the upmost whit and intelligence. The Dirty Mom has three parts, investigation, identification, and execution. Every group of friends has the one friend who has the "really hot mom". The Dirty Mom requires that a friend secretly break into the "hot mom's" bedroom while she is away, and find the one personal thing(s) that belongs to her that she would be devastatingly embarrassed should anyone find it (which every woman has). Then, when the opportunity arises, bring that item(s) to her attention and bribe her into sex, under the assumption the personal item will be returned after, and that no compliance will result in her secret being revealed to the world. She must agree to the deal, and thus, execution follows. When you keep up your end up the deal, return the item after the sex, and keep your mouth shut--- you have succeeded in completing the Dirty Mom, or, the Dirty Mother.

When your mom is a shut and ducks her biological sons penis

The act of participating in every form of sexual intercross with your mother.

When someone says "ya moms dirty" they're saying that ya mom got fucked or just has cum / smegma on her

When your mom has cum on her