Collaborative sex stories let us write the plot together

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

Your step-sister sighs. “Okay, I’ll fuck you in the bedroom. It’s silly anyway. But I have one condition.”

“And that is?” you ask her as you feel the blood rushing up your dick.

Amy looks at Rachel. “I’m sorry, but my condition is that only my brother and I go in the room.”

Your girlfriend gives you a look as she considers. Then she turns back to your step-sister. “Fine.”

You quickly kiss Rachel before dragging Amy to your room and locking the door. You grin and immediately moved in to kiss her. She makes no attempt to reject you.

You start Frenching her and slowly back her up to the bed. Amy falls back and you leap on top of her. You rush to pull your pants down, and in half a second your fully-erect cock is on display for her.