Aunt Ruth
A person is referred to as an “Aunt Ruth” when they are scheming a situation for personal gain/to take advantage of a situation involving friends and/or family. Considered an insult. A male or female may be called an “Aunt Ruth” if they are found to have developed such a plot to scam, con, or otherwise take advantage of friends or family. Can be used in various contexts to get your point across.
“Are you seriously going to Aunt Ruth us out of our inheritance?”

“Stop being an Aunt Ruth”

“Somebody need to tell Aunt Ruth over here to slow her roll”

“Get yo damn hand out of the cookie jar Aunt Ruth”