Collaborative sex stories let us write the plot together

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

“Amy, is it really so bad that my girlfriend wants to involve you in our sex lives?” you ask her.

“Ross, it’s not that I don’t still think about you — not that I’m thinking of you all the time. It’s just it’s been so long, and I’ll admit I’ve missed it but… erm…” Your step-sister’s composure is slipping.

“Do you want a shovel, Amy? You’re digging yourself in as it is,” Rachel jokes. Amy blushes rose-red.

“Rachel, I just want to ask you — as your closest friend — are you one-hundred-percent certain you want this?” Amy asks, looking directly at Rachel.

“Absolutely, Amy. Besides Ross, you’re the only person I’ve ever wanted this with,” Rachel answers, speaking as clearly as she can.

Amy smiles “Then I’m fuckin’ down for it, too.”

Your heart leaps as Amy begins to strip off hastily. Her boobs look as fat and soft as ever, and the rest of her body has matured very nicely. She’s even kept her pubic hair trimmed in the same triangle.

“Wow, Amy… you look sexy as fuck!” Rachel comments.

“Rachel, you’ve seen me in lingerie before now,” Amy reminds her.

“But never naked,” Rachel points out, smiling. “So Ross, where shall we do this?”

“Not the bedroom,” Amy tells you. “Remember the rules, Ross. I have.”

In answer to your girlfriend’s confused look, Amy clarifies, “We never had sex in a bedroom. Too matrimonial.”