When you are in a body of water such as an ocean and a man lays his penis on ur shoulder like a purse strap
by Bridget ellerby October 30, 2018
"Oh Laura, don't tell me you're gonna let that dude get inside your mermaid purse just because he changed your tire?"
by monroe1962 May 25, 2009
A Mermaid's Purse is when an individual defacates into a womans vagina, the woman then hovers over the face of the individual and lets it fall onto his or her face.
John and Linda wanted to spice up their relationship so during sex, he took a hot, steamy, crap in Linda's vagina and she reciprocated by giving John a Mermaid's Purse.
by Kenty G. June 20, 2006