Yes, everyone in this story is at least 18 years old
She lay on the bed and looked down, past her perfectly formed 36-DD breasts standing proudly on her chest. She gazed past her ridged abs, the product of hours in the gym. There she saw what was making her feel so good -- one of her nerdy son's (no, STEPson's) friends, plowing into her with his enormous dick.
Two more of his nerdy friends (all of whom were somehow 19 and geniuses, yet still in high school) looked on, stroking their fourteen-inch cocks as they awaited their turn. Her geeky stepson cackled as he played with his phone. "See, I told you guys that this MasterPC thing was for real!"
The boys took their time with her, and of course she had massive orgasms every time they entered her. She even had a nice cum when they covered her massive boobs with jizz as they finished up. What a nice way to spend an afternoon!
She took a long, hot shower, reveling in running her hands over her perfect MILF body, thinking about the day before. It was so nice that all of her suburban housewife friends also had perfect MILF bodies and they all liked to gather at one of their pools (they all seemed to have pools) and drink wine and have hot lesbian sex. That is, when they weren't at the gym, or taking their nineteen-year-old sons to high school baseball practice. Maybe one of the boys should learn to drive.
She slipped a sheer robe over her sexy body and went down to prepare dinner for her family. She peeked into the den as she walked past, seeing her husband (or was that her stepbrother?) sitting on the sofa, her nubile barely dressed nineteen-year-old stepdaughter sitting on his lap, lewdly grinding herself on his crotch.
As she cooked dinner, she could hear her stepdaughter crying out in ecstasy. "Oh, Uncle Stepdaddy! Your cock feels so good in my little virginal pussy, like it does every time you fuck me!" It was nice that they were getting along so well together. And it was not at all weird that absolutely no one in her little family was actually related to one another.
Dinner was a great success, if she judged by the groans coming from her stepbrotherhusband and her stepson, and those loud slurping noises, coming from... somewhere. She wasn't sure where her stepdaughter had disappeared too so quickly though -- she probably needed to study.
After dinner, her stepson headed over next door to that lovely divorced woman's house to help her hang some curtains or something. She always seemed to have things that needed to be done around the house. And he was such a good boy.