Portia

 is a witch who is Tabitha's friend from high school.

She tries to seduce Marvin Decker, Tabitha's boss, and places him under a spell with a magic coat, regardless of the fact that he is already a married man with a son.

Tabitha remembers that Portia has no sense of humor, and humiliates her by casting a spell Portia cannot undo, so she pops out in a huff.