Is there any content out there that focusses on mother-son femdom?
Or maybe a close facsimile, like stepmother-stepson. Or even that presents it as a roleplay, where the mistress takes on the role of "mommy," and forces you to live as her houseboy.
I suppose what I like about this fetish is that if it developed in real life, it would make you unable to function as an adult. Boys start keeping their distance from their mothers to become independent; they get embarrassed by being mothered and shrug it off. But I like the claustrophobic, restrictive, humiliating side of being a mama's boy, at least as a fantasy.