piss on

Verb

 * 1)  To express contempt and disrespect for someone or something, or to act accordingly.
 * 2)   To reject (a person, an idea, etc.)
 * 1)   To reject (a person, an idea, etc.)
 * 1)   To reject (a person, an idea, etc.)
 * 1)   To reject (a person, an idea, etc.)

Usage notes
Unlike the structurally similar and, this expression is often used imperatively. In these sentences, piss on behaves like and, and the subject is always omitted. However, the formation piss on me is uncommon.

Although the euphemistic pee on can carry the same meaning, it is uncommon even among those otherwise prone to euphemisms; other expressions are more commonly employed in its place.