Reciprocal/mirror sibling incest?

[000zing]

Would it make for a reasonable story plot? A brother and sister find their soul mates in a sister and brother from another family. The two families are overjoyed at the quirky prospect of simultaneous joint weddings and this duly takes place with a huge reception being held. Etc. etc...

A few years down the line and the promised grandchildren have not arrived from either union. The marriages are both frayed and on the verge of breaking up.

I'm looking for a scene/mechanism whereby the original brother-sister pairings end up in long term, incestual relationships, each believing the others (and of course the two families) are not aware. Children are produced and... well, I'm not sure where it goes after that!

Any thoughts or ideas to make this run?

 

[Carnevil9]

The plot is probably going to feel a little bit contrived, but that's okay. Just don't take things too seriously and it will be a big hit with the incest fans.

You can have fun with the children not looking at all like their fathers but more like their uncles!

 

[NegateGivity]

The plot is probably going to feel a little bit contrived, but that's okay. Just don't take things too seriously and it will be a big hit with the incest fans.

You can have fun with the children not looking at all like their fathers but more like their uncles!

And having hemophilia, like the finest of Europes nobles.

 

[Magineer]

Too contrived, as Carnevil says - certainly for my liking. Still, stranger things have happened and it's hardly the job of imaginative writers to focus on the completely everyday and mundane. Go for it, why not?

 

[sirhugs]

Lit readers seem to be fairly forgiving of contrived.
Perhaps the first pair of siblings get carried away when she comforts him over thinking his marriage is failing.
After thweir frolic, she feels guilty, so gpes for coffee with her sister-in-law while her hubby has a beer with her brother. Except wires get crossed, the secomd sister ends up having a beer with her brother, leading to several more and parking lot sex. Meanwhile, the first pair of siblings skip the coffee and go straight to round two...

 

[000zing]

I was thinking we might somehow get the original brother-sister pairings together sexually via a single event in which it all kicks off without the married pairings realising what is happening. Each actual bros-sis pair thinks it's putting one across on the other. Perhaps it's been the two couples' "tradition", since the weddings, to have a monthly candle-lit dinner together..? Could it be taken from there?

 

[sirhugs]

I was thinking we might somehow get the original brother-sister pairings together sexually via a single event in which it all kicks off without the married pairings realising what is happening. Each actual bros-sis pair thinks it's putting one across on the other. Perhaps it's been the two couples' "tradition", since the weddings, to have a monthly candle-lit dinner together..? Could it be taken from there?

one pairing wangers off to use the bathroom at the same time, end up hooking up. Rather than go to look for them, pair two gets busy on the couch until they hear pair one coming down the stairs...

 

[SteelPoint]

Another one for the "too contrived" lobby. Seems to me you'd have to introduce a lot of other material to distract the reader from the symmetry - things which would render the two married couples distinct from each other.