Looking for an existing story

Sometimes I like to go back and reread some stories I've already read even though I already know the story and there's been one that I've been looking for recently (I usually like to look for at least a week before I ask here)
The story is family related (figured I'd put that out there immediately) It's about a guy that if I remember right is described as ripped who completely submits to his mother and sister by choice (if I remember correctly it was literally his choice not them forcing him to "choose" it) and at some point in the story he has his sister taser his nuts