Collaborative sex stories let us write the plot together

(Her Secret Fantasy, continued by Duo...)

At this point, attempting any more vaginal sex will end up the same way. You have an idea, since you’re still freakishly hard.

“Hey, my dear sweet step-sister, you wouldn’t mind cleaning my cock off, would you?”

Even with a bloated belly full of your seed, Amy’s eyes spring open at the prospect. “Oh, I’m so thirsty,” she moans, and that’s good enough for you. You maneuver her up on her knees, and bring her to the couch, where you sit with your manhood jutting into the air, and then, in one movement, she buries her mouth all the way to your balls with little other than one single gag. Then, she takes you out, then in, out, then in.

She does so well, you swear she’s practiced this, as your balls start churning, and you feel yourself close to orgasming again. You finally grip her hair and explode in her mouth, and just like the last few times, you simply keep cumming, but this time, just hearing the swallows from your step-sister eggs you on even more.

Eventually, you stop cumming, though your hard-on still surprisingly exists. Another look at your step-sister reveals that her gut is even bigger than before, and jiggles back and forth like jello. You look at your girlfriend and Monica, and you can see they’re very anxious to resume.