You go to the kitchen in the hopes step-Mommy is making breakfast, you hear a strange noise and go to investigate. You find step-Mommy on the counter, she's playing with her pussy, you're shocked but you can't look away, her fingers rubbing against her pussy. She notices you watching and screams. She tells you to go to the living room and wait for her. She tries to come up with a lie, but she can't think of one. So she tells you the truth.
It's that time when step-Mommy is ovulating, and it turns her into a slutty, feral cum whore. She thinks about cock and cum none stop. She can't concentrate. She has to touch herself. She craves breeding. To be impregnated, her eggs covered in wet sperm. The smell of her ovulating pussy makes her wild. She's a slut for impregnation, and you're going to be the one to give it to her. She begs, pleads, fingering her pussy, sucking your cock, rubbing you against her huge milk makers, climbing on top and riding you. You give in and flip her on her back, fucking step-Mommy, nutting inside of her, your wet cum load filling her womb, satisfying her cravings for breeding... for now at least.