When I was thirteen, and in the throes of constant hormonal urges, I discovered that my step-mom's father was a pedophile! They sent me to his place in the country, during school recess, with instructions to obey him utterly and instantly, as he was going to summer-school me in mathematics, my grades being so awful! Then they went on a cruise! Grandpa Miller was a small wiry man, a health freak, who was sixty, going on thirty, and a real asshole of a man, who was loud and crude in his behavior and language. I quickly discovered that the punishment for any infraction of his 'rules' was confinement in a big old bag of rubberized canvas, olive drab, and six or seven feet long! "Lessons" took place from outside the bag, and any lack of enthusiasm or cooperation, led to many hours of such confinement! I got over my fear and repulsion quickly, as there was a small zippered opening at my mouth, and another one at my crotch, enabling me to be fed, hydrated and allowed to pee, quite efficiently! Then one day he opened the crotch zipper, pulled my goodies outside, and closed the zipper tight round the roots! Then I discovered the REAL version of what I had been fumbling fruitlessly with! "You like that, eh, you little bastard? Well, get used to it! There's gonna be a LOT of it!" He wasn't exaggerating! There was a whole summer of it! And when he had me thoroughly addicted to this wonderful new discovery, he began pushing HIS erect cock into the zippered opening at my mouth, and I learned very quickly how to suck the invading monster, to his complete satisfaction! Discovered I liked the feeling of this too! The summer passed in a flash, it seemed, and I was returned to the everyday rut, with the comment that I was a real slow learner, and ought to spend every weekend and holiday at his place, being instructed in the finer points of mathematics. My parents were delighted, as it gave them the freedom to go all over, as was their preference! I was delighted, and dreamed all week about the big bag that was almost my second home! Now, fifteen years later, Grandpa Miller is no more, and I am married to a real "controlling bitch" who takes my pay-check, has everything in her name, and revels in her ability to keep me in the same old bag, evenings, weekends, and vacations! I love her to death!