mistressing Posted in M Best definition mistressing The job of being a mistress. Similar to how a waitress would say she performs waitressing for a living. I’ve been mistressing with the same guy for 10 years now. The guy just can’t get the balls to leave his wife. How satisfied are you with the definition? Looking for mistressing meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 12 times.