Identical twins marry identical twins


Tthis actually happened:

First the headline: Twice Upon a Time: Identical twin sisters, 32, marry identical twin brothers, 34, in a fairytale ceremony in Twinsburg wearing matching dresses and presided over by identical twin ministers… and now they will all live in the same house

(Are they really “all” going to live together? I don’t know how I’d feel about living with a couple of ministers… :wink: )

My question is if this is permitted in the Church? Marrying the brother of your sister’s husband?


Near blood relations and godparents are the only impediments to marriage from who you can marry on the basis of relationships.


What possible reason do you have that this would not be permitted?


I don’t even think godparents are an impediment anymore under current law. Direct relations (children, grandchildren, parents, grandparents, great-grandparents, great-great-grandparents) are considered permanent impediments by divine law (and thereby cannot be dispensed) but impediments in the collateral line are of ecclesiastical force and can be dispensed (with dispensation, it is permitted for first cousins to marry).


In Church law maybe, but I know some countries and US states still do not permit first cousins to marry.

Back to the article, nothing wrong with that. It’s weird for many of us sure, but not that uncommon.


Yes, of course, I’m referring only to canon law. I cannot comment on the whole gamut of civil law around the world.


Thanks everyone! I had no idea what the rules are, so wondered.


I’m pretty sure there’s a canon law that says, if you marry A, you can’t go on to marry A’s brother if he dies. That’s one of the things that came up when Henry VII wanted his son, the future Henry VIII, to marry Catherine of Aragon, who had already been married to Henry VII’s older son, Arthur, for about five or six months before he died. They had to get a Papal dispensation for it. Catherine had to swear that the marriage had never been consummated, etc., and therefore was not an impediment to her marriage with Henry VIII. But even so----

Can. 108 §1. Consanguinity is computed through lines and degrees.

§2. In the direct line there are as many degrees as there are generations or persons, not counting the common ancestor.

§3. In the collateral line there are as many degrees as there are persons in both the lines together, not counting the common ancestor.

Can. 109 §1. Affinity arises from a valid marriage, even if not consummated, and exists between a man and the blood relatives of the woman and between the woman and the blood relatives of the man.

§2. It is so computed that those who are blood relatives of the man are related in the same line and degree by affinity to the woman, and vice versa.


Can. 1091 §1. In the direct line of consanguinity marriage is invalid between all ancestors and descendants, both legitimate and natural.

§2. In the collateral line marriage is invalid up to and including the fourth degree.

§3. The impediment of consanguinity is not multiplied.

§4. A marriage is never permitted if doubt exists whether the partners are related by consanguinity in any degree of the direct line or in the second degree of the collateral line.

Can. 1092 Affinity in the direct line in any degree invalidates a marriage.

Can. 1093 The impediment of public propriety arises from an invalid marriage after the establishment of common life or from notorious or public concubinage. It nullifies marriage in the first degree of the direct line between the man and the blood relatives of the woman, and vice versa.

Can. 1094 Those who are related in the direct line or in the second degree of the collateral line by a legal relationship arising from adoption cannot contract marriage together validly.


So, your father-in-law is off-limits, because he’s in the direct line. But your brother-in-law used to be off-limits (ie, Arthur and Henry), but no longer is, because he’s a collateral line.

Here’s a nice article that talks about what things have and haven’t changed. Things may have been more restricted in the past— my affinity-relationships would also affect the affinity-relationships of my blood relatives-- but I don’t think that’s been the case for a long time.

Prior to the Fourth Council of the Lateran (1215), the Church recognized two additional forms of affinity.[8] Firstly, when a man married a widow, her relatives as well as those of her former husband were considered the man’s relatives and treated as if they were his blood relatives.[8] Secondly, if the woman’s first husband had been a widower then the blood relatives of his first wife became the woman’s relatives and by her subsequent marriage, were also the new husband’s relatives by affinity.[8] Also, a woman’s children by a deceased husband, as well as the children of her husband by a deceased wife, were considered related by affinity.[8] So the subsequent marriages of step-siblings carried the same prohibitions as if they were related by blood. The principle established was “affinity begot affinity.”[8]

The Fourth Lateran Council removed the second type of affinity rule and the new axiom became: “affinity does not beget affinity”, which is the principle followed in the modern Catholic church.[8] It also limited both affinity and consanguinity prohibitions to the fourth degree, but retained the same method of calculating, counting back to a common ancestor.[10] The Council of Trent (1545-1563) limited the impediment to marriage on account of affinity in cases when the affinity is created out of marriage (e.g., by force or extra-matrimonial intercourse) to the second degree of affinity.

So— I think the twins are okay, because we no longer treat our siblings’ in-laws as blood relatives, even though we may have, once upon a time, when people were more concerned about limiting how much intermarrying took place in a limited geographic area, and when political dynasties were more of a “thing”.


Wow, all that is dizzying! Thank you for looking all that up and posting it :smiley:


I can think of three marriages in my extended family/family friends where two sets of siblings married another set of siblings. It would be nice to have my sister as my sister in law! (not that I do not love my in-laws or want to swap them out).


Under the current code of canon law, yes.

Historically, there have been various impediments within the context of affinity. These are ecclesial impediments, so even then they could be dispensed.


From memory, without attempting to look up any references, many Christian countries had (or possibly still have?) a long-standing prohibition against a widower marrying his deceased wife’s sister and a widow marrying her deceased husband’s brother, in contrast to the Mosaic institution of Levirate marriage (Luke 20:28). But I don’t think this ban would extend to the case here of the twin sisters who married twin brothers.


Here is a curious aside – relationally the children born of two such marriages would be cousins, but genetically they would be like brothers and sisters.



I agree with what’s been said here. But I think these couples are nutty. Getting engaged on the same day, living in the same house. These people need more individuality. Next thing we’ll learn, they will have conceived their respective children on the same day.


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