The first day.

You tried to continue your conversation, but your sister interrupted.

"Are you hard right now?" She asked.

"What, no." You tried to lie but didn't sound convincing.

"You are. Thank God, I thought I was the only one who got horny in here. Were just coated in vaginal juices, and unbirthing is meant to be a popular kink, I think I have it bad, but I have only ever done it with mum and that seems wrong to enjoy." She explained. "I thought it would be super awkward to try and masturbate with you sitting there. That's what I normally do, at least at the start, when I'm in here."

"Me too." You added agreeing to the kink and wanting to masturbate but being vague about it. "Let's just turn our backs and pretend the other is not there. Like we did as teens before we got our own room." You cringed at your own memory.

"Ok." She agreed and turned her back.

You turned your back and began to stroke your cock. You tried to ignore the moaning coming from your sister bit it kind of turned you on and helped. You were grateful that you could just pretend it was porn or something. You quickly reached orgasm, spurring in your hand and onto the walls of your mother's womb. You were not worried, with you attached by an umbilical cord, her body acted like she was pregnant, so it was impossible to get her pregnant. A few moments later, you heard your sister scream as she climaxed.

Relieved for now, you turned back around and, without acknowledging it at all, went back to your conversation about how unfair it was that you both got fired just as a crisis hit.