Step-Mommy's burping domination.
Maria's step-son (POV) is weak and quite pathetic; she's always been embarrassed of him, no matter how hard he tried pleasing Step-Mommy. Today, the punishment is going to be exquisite, not to mention pure evil: Maria is going to her step-son to smell her stinky burps, all the while encouraging him to stroke it for her and for her explosive belches. He goes soft on her, she tells him, and there will be hell to pay. Maybe after this Maria's step-son will be begging for her burps instead of cringing at their smell, at their suddenness - just maybe x