I suspect that my ex did, but kept it all in the family. Early on min our relationship I had to go out of town on business. She had her adult stepson sty with her "because she didn't like to be alone. Right! If she was alone, her pussy would not get any attention!
She told me that she had a fantasy of teaching a classroom of young boys how to please a woman. One by one they would come up front and she would train them. She emphasized that it was only a fantasy. I suspect it was more than that. I suspect she trained her boys and she continued behind my back.