John Doe and Jane Roe get married. What’s the relationship between Papa and Mama Doe and Papa and Mama Roe? That’s what’s being talked about.
My sibs and respective spouses have discussed this in the past. We thought “out-law” or “by-law” would be better than “in-law” in these cases. 
I vote for Italian, because their words are so melodic.
Plus, we can steal some cannoli while we’re at it! 
I always say my sister-in-law’s brother and I are “nothing by marriage.”
Outlaw sister.
I got confused when my mother-in-law re-married. Does anyone actually use the term “stepfather-in-law”?
She’s your sister.
In jest in my family, we sometimes call that relationship sister-in-law-in-law.
My brother-in-law’s wife and I call each other “the out-laws.” (We called my sister-in-law’s ex-husband “the jerk.”)
I just call 'em all sister-in-law.
I have 3, plus 3 SIL’s on my side. That makes one Jhetani and two Devrani–what do I call my younger brothers’ wives? I haven’t got an older brother, or I could collect them all.
While we’re at it, does anyone other than my extended family have a term for one’s cousin’s cousins on the other side? Like, Alice and Bob are siblings, and Carol and Dave are siblings. If Bob and Carol marry, then their kids will be cousins to both Alice’s kids and Dave’s kids. But what’s the word (if any) for the relationship between Alice’s kids and Dave’s kids?
Korean has about eight different terms for siblings depending on whether the sibling is older or younger than the speaker, and whether the speaker is male or female. It also has two ways to say “uncle,” one of which can simply mean “middle-aged older man.” There also are two ways to say “aunt,” whether she is maternal or paternal.
So what relation is your father’s brother’s nephew’s cousin’s former roommate?
Actually it’s much more specfic than that. Korean differentiates between aunts and uncles by blood and aunts and uncles by marriage, as well as by whether they are paternal or maternal. Also between your father’s brothers that are older than him and younger than him, and whether they are married or not.
For example, my mom’s brother I call weh-sam-chon but my mom’s sister’s husband I call ee-mo-bu and my dad’s older brother I call keun-ah-bba but his little brother I call jak-eun-ah-bba (but sam-chon before he got married) and his sister’s husband I call go-mo-bu. In English I would call them all “uncle.” :eek:
Brother’s wives are “Bhabi”. Either you have “Badi* Bhabi” which is an older brother’s wife or “Choti Bhabi”, younger brother’s wife.
*The d signifies the rolled heavy r in Hindi dialect.
And your kids? They call your brothers “Mama” (mother’s brother) and their wives “Mami”. Your brother’s kids are your kids siblings, though - we don’t really differentiate for cousins. Their kids are your “bhanja” for a boy and “bhanji” for a girl.
I could go on. Your kids are a different word for your brothers; “bhatija-bhatiji”. That way we know exactly, it’s your brother/sister’s son/daughter. Very specific and the way it should be IMO.
I’m cool with stealing from Italian. It has a certain je ne sais quois. 
But really I don’t care where we grab it from. Hindi has plenty of words to steal form.
Hazel, Mandarin Chinese is like that too.
ETA: One more thing - yeah, we have a word for what the parents-in-law are to each other, too. “Samdhi” and “Samdhan”.
OK, so I have three Choti Bhabi. Excellent.
My kids will be thrilled to hear that they have so many siblings–they want to live with their cousins anyway.
Crazy bitch.
Oh, wait! You’re not talking about my brother in law’s wife specificially!
Absolutely nothing!
Never knew what “twice removed, etc.” meant. Till now. Any other languages use this?
We say outlaw too, but not in a serious way, obviously. We’re quite good friends with my partner’s sister’s husband’s brother, and he’s the outlaw that we use that term for most often.
Of course, I refer to my partner’s family as my inlaws despite us not being married, so it’s not as if we’re abiding by technically correct nomenclature anyway.
Which is what you will be soon!
Damn you, EvilTOJ - I opened this thread specifically to use that quote.