Author's note: Despite the title, this is NOT a blood-incest story. I only write pretty vanilla stuff. The title popped into my head when I was thinking about the ending.
I'm putting this in the humor and satire category because, interspersed with a few titillating scenes, the story revolves around a minimally sexy act of sex, and inverts a lot of tropes like cheating, three-ways, non-blood incest, and so forth. I had started it intending to follow the trope of "dykes discover dicks" but decided that was a little disrespectful, and I had to consider the characters and their motivations - it just wasn't going to work as plain erotica and was much easier to write this way.
Also, all discussion of reproductive biology is as made-up as the sex, so, duh, please don't be mean to me, especially if your initials happen to be EC and you make brownies that give me a mouthgasm.
We were reading in bed, quietly, when my wife turned to me. "Jack, honey, I have a pretty big favor to ask of you."
I nodded my willingness. "Sure, love, anything you need."
"I need you to fuck my sister."
Those were not words I ever expected her to say. For one thing, I only fuck my gorgeous wife Margo, and haven't dallied with anyone else, nor wanted to, since before we met. For another thing, her sister Elspeth is happily married - to another woman.
"What?"
"Elspeth and I were talking about her desire to have a family with Anne. They had been discussing whether to use a sperm bank, have an anonymous hookup with a random(ish) man, and hope it worked out, or to try to choose a particular donor."
"Let me guess..."
"It was actually Anne's idea. She loves our kids, Elspeth's nephews, and that put the bug in her bonnet."
"Wait, so my sister-in-law's butch lesbian wife got baby fever seeing Miles and Felix, and now you
need
me to raw-dog your sister?" I did an imitation of that blowhard cartoon chicken, Foghorn Leghorn.
"That, my dear, is preposterous."
"That's not preposterous enough. You also have to raw-dog Anne."
Anne could have been on the cover of a fashion magazine called
Bull Dykes In Flannel
. She drove a Subaru, had very short hair, baggy jeans, Doc Martens, all the body hair Nature gave her, and enough piercings that she had to be very careful to remove them all before trying to go through airport security. Underneath that tough-looking exterior was a physique toned by daily workouts, and gifted by Nature with a shape that was unmistakably female.
On the surface, you'd never think of Anne as being the slightest bit interested in motherhood. But the style she adopted was just her way of being flagrantly out. She was also a warm, funny, and nurturing person who actually, now that the thought was allowed to enter the realm of possibility, would probably be a pretty good mom.
"Also?"
"They both want the experience of pregnancy. I understand -- it's a powerful, powerful urge. And I know you used to find my sister attractive."
That's true. I had been introduced to Margo after three really fun outings I had considered to be "dates" with Elspeth. Those put us in a good friend-zone relationship, and Elspeth, after the third no-that-wasn't-a-date, came out to me, telling me "That's why I never considered these as dates -- the thought literally didn't enter my mind." She hugged me, and said she thought her big sister might like to meet me.
Six years later, Margo and I had a toddler and a preschooler, and Elspeth needed a sperm donor.
"I am going to have to think about this."
"You know I wouldn't consider it being unfaithful."
"I know. And I need to process that myself, and ... wow. I mean, it is a lot to consider."
"I know, honey. And we can talk it over a lot, between ourselves and with them." Margo reached down and fondled me through my pajamas. "Right now,
I
need a sperm donor." She'd had a surgical sterilization along with the C-section that gave us Felix, and I was more than happy to send my sperm on a futile quest to her dead-end Fallopian tubes.
In the morning, I had done some thinking. "I guess I could be a sperm donor for them. If I trusted anybody to raise my offspring other than you, it would be those two." I winked at her. "Especially if you help with the collection process."
"That's the hard part. They don't want to do artificial insemination. I don't understand it either, but they have persuaded themselves they want to start their babies the old-fashioned way, not even the turkey baster method."
We were definitely going to have to do a lot of talking to work this out.
"I guess we should start by having them over to dinner, this is going to need group thinking. Not just technical infidelity, but possible emotional consequences, legal paternity, so many issues."
"How's tomorrow? We'll have them over, which the boys will love, and then talk after we put them to bed."
"One thing though -- we are
not
going to have sex tomorrow night."
"Not even after they leave?" Margo grabbed my butt and squeezed.
"You are correct as always, dear. Can't rule everything out."
Margo made her mom's "famous" lasagna, which was a family favorite of all six of us. Elspeth and Anne brought a few bottles of red wine. I wrangled children and made a salad and garlic bread.
Felix was covered in tomato sauce from forehead to bib, but allowed Aunt Anne to wipe his face without complaint. Miles was getting pretty good with a fork once things had been cut up, but was still a bit of a mess.
Margo took Felix off for a bath. Miles asked if Auntie Anne could read him his bedtime story (Did I mention she'd be a good mom?), and Elspeth and I were on cleanup duty.
"You know Anne. She's researched the hell out of this. For one thing, clinic insemination is only about half as likely to result in conception as unprotected sex, when both are done during the window of maximum fertility. Children of lesbian parents who have a relationship with their donor are thought to be slightly better adjusted than those who were conceived from an anonymous donor, although that's not absolutely established. And clinic insemination is costly, with no guarantees. Many women have to make multiple visits, and it's rarely covered by insurance.
"And why you specifically? You are a very nice guy, I'm glad you're my brother-in-law, and if I was straight I would for sure have kissed you after what would definitely have been a date. And you made beautiful babies with Margo. Anne has no brothers. So for related, fertile men you're it."
"And what if, six years ago, a magic fairy had told you that one day you would want to have my babies?" Elspeth laughed with me. "I would be totally down with giving you my DNA, knowing who the moms were going to be. It's the intercourse part that makes me leery."
"That made Anne and I leery too. Neither of us has any interest in penises, even if they are attached to you." She smiled and blushed. "That's why we want a threesome."
"Did you happen to mention that to your sister?"
"Not yet. If you'd vetoed it, I'd have dropped it. If you're willing to consider it, of course she will have to be involved in the discussion."
Anne and Margo had been having their own conversation as they came down from putting the boys to bed. They poured some more wine and passed us the bottle.
"Margo, my love, there's one more thing. Both of them are turned off by penises, and they want to have a threesome."
"Aside from the sperm donation part, we'd be making love with each other and Jack would just be a meat dildo. No offense."