Abigail Loraine Hensel and Brittany Lee Hensel (born March 7, 1990) are American conjoined twins. They key thing here is that they (are female and) have '1 set of reproductive organs' unlike
females with 2 vaginas like Hannah Kersey or Hazel Jones
conjoined twins with separate sets of reproductive organs like Lucio and Simplicio Godina and Carl and Clarence Aguirre.
- BTW, both twins are conjoined twins from the Philippines, the only Catholic country in Asia besides East Timor. Even though they're a different case from Abby and Brittany, I don't think you can say Catholicism hasn't encountered at least a similar case.
Question: So what does Catholicism say about marriage for conjoined twins like them who share reproductive organs: Can they indeed get married (to separate males)?
In particular, are they indeed allowed to have sex with their respective spouses even if obtaining carnal knowledge of 1 twin is equivalent to obtaining carnal knowledge of the other? Like... If Abby marries Carl and Brittany marries Daniel, then can Carl / Daniel have sex with Abby / Brittany even if it means Carl / Daniel would be obtaining carnal knowledge of Brittany / Abby?
Consider the following scenarios that may arise (as guide sub-questions, not necessarily the main points) :
If Carl and Abby are allowed to have sex and they do have sex, then after they are done, can Brittany and Daniel begin right afterwards? Can all 4 do it at the same time like alternately? Or does it have to be 1 pair after the other?
If Brittany isn't seeing anyone, then is it wrong for Brittany to ask Abby to have sex with Carl on a day Abby and Carl weren't particularly intending to have sex (but then Abby and Carl of course consent anyway) because Brittany wants sexual pleasure kinda like how Jews would ask non-Jews to operate electrical switches?
Aha! I found out that Judaism SE actually has a post for this. What is the halachic status of adult conjoined twins? Your move, Christianity SE! XD