Collaborative sex stories let us write the plot together

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

“Well, I was hoping that Amy would get back to me soon,” Rachel says casually, reaching for her phone.

“Wait, Amy?” you exclaim. “You don’t mean-”

“Your step-sister, Amy. Yes,” Rachel tells you. “Haven’t I told you we’ve been friends with benefits since before you and me dated?”

“Umm…no…” you answer, not sure how you’re feeling about your girlfriend fucking your sister.

“Oh, well now you know,” Rachel says simply. “Okay, I’ve got a reply from her — she says she’s fine with hooking up with me, as long as you agree to it.”

“Hang on, how long have you two been friend with benefits, again?” you ask, hoping you sound casual.

“I think before you and me even met. I remember her taking my lesbian virginity on my nineteenth birthday…” Rachel thinks hard, but the memory of her nineteenth seems to calm her down. You can see why this is so important to her. “So, what do you say? Are you okay with me and Amy fucking?”

You find yourself taking quite a while to decide on an answer. On the one hand, it sounds sexy as hell, and you know how much this would mean to both women. On the other, you don’t know if you can stomach the thought of your girlfriend eating your step-sister out or vice-versa.