Oh, I see— “it’s not true because I say it’s not”. Got it. Thanks for clearing that up 
I will concede you do have a good point that, practically speaking, I do see my wife’s siblings’ spouses at family events much more often than my sisters’ husbands’ siblings.
I’m guessing we don’t have a lot of words for it because it’s not important to us (as a whole). If they have those kinds of words in Farsi, I’m guessing it either was, or perhaps continues to be, important to them. Whereas for us, it doesn’t really matter all that much.
No, that’s not what I’m saying. It’s a word. My group uses the word to mean this. Other groups likely differ. There’s no real reason for the difference. If you had posted “This is what my group means by this word.” I wouldn’t have argued against it, but you were replying to me describing what the word means to me.
Per my wife, when you’re in a traditional village culture, your prospective spouse must be found in the combined population of 300 immediate neighbors and at best 1500 more people from the surrounding area. Under those circumstances it’s very important to know exactly how one might be connected to others.
My wife considers my brother’s wife her sister-in-law and their kids her niece and nephews. But SIL’s siblings? I’m not sure I ever met any of them and do not consider myself related to them. Now I do use the phrase collateral relative for any relationship created by marriage.
Incidentally, I did use the word stepfather for the man my mother married after my father died, even though I was 35 at the time. Although I called him by his first name.
A collateral relative is any blood relative who is not a direct ancestor, nor your direct descendants. So your siblings, cousins, nephews, etc.
It’s all a matter of taste and preference, as far I’m concerned. I like the person I described above as my “cousin” and he appears on my family tree if I extend it far enough (as does everyone on Earth, I suppose) so I enjoy introducing him as my cousin, or sometimes “my distant cousin.” If you want to argue with me, suit yourself. I enjoy that conversation, especially if you get all red in the face as you tell me how wrong I am.
I wouldn’t consider myself related to my in-law’s siblings but I absolutely know them and the only way I wouldn’t know them is if one of us never showed up for events in our common relatives lives - if I go to my brother’s wedding or his daughter’s birthday party or my brother and sister-in-laws’s summer BBQ , I’m going to see his wife’s siblings there unless those siblings never show up for events. Same thing for “turkey cousins” ( your cousin’s cousins on the other side of the family, who you only see on holidays)
The relationship i need a name for is my child’s parents-in-law. We see a lot of them, and they feel like relatives (by marriage).
My mom had a similar relationship with the parents of her children’s spouses.
I’m okay with “cousins” for distant relatives by blood whose outside relationship is far enough that the details don’t matter. But “cousins” feels wrong for this one.
What does that make us?
Yiddish has a great one: machatunim
Bengali also has terms for these situations.
Even better in the singular: machutainista.
I have a number of relatives on my husband’s side that I refer to as my cousins. His cousins, their spouses, their children, their grandchildren – all cousins.
Yes! “Turkey cousins” is spreading!
(unless you’re one of my extended kin, I think I’m the one who introduced this term to the board)
My stepfather became part of my life when I was 31. But he was very kind to me, always remembering my birthday, and he loved my mother. She was a widow for more than 20 years, and he made those years joyful. It was not his fault my father had died.
More to the point, he was the only “grandpa” my son knew. He was as much a grandpa to my son as he was to his bio grandson. He was a 30 year Navy pilot, who took my son to his old drill halls (or whatever they were called) and introduced him to everyone as his grandson, and showed him everything about the planes he was interested in, and finally took him on a short flight (he was just a passenger, and the pilot was a current Navy man, but he took my son into to cockpit and explained everything that was happening).
More than anything, that cemented my fatherly feelings for him. Certainly, I would have preferred to have my own father there, but my son was always glowing after days with “grandpap.” And the boychik doesn’t know the difference. I had to think about him.
After my mother died, my stepfather has continued to send cards and gifts to my son. We have not had a lot of visits due to COVID, but we send lots of baked goods, especially around holidays, when my mother would have made things.
I love this man. Perhaps not really like a father, since he did not raise me-- more like a favorite uncle. But he is important in my life. People who come into your life when you are an adult can still become very important.
My sister-in-law’s sister is also my sister-in-law. It’s a little exceptional, though-- she has Down Syndrome, and while she is currently in her mother’s custody, it reverts to my brother and his wife whether her mother dies.
Currently, my brother’s MIL lives with him and his wife rent-free, but does all the housework and most of the cleaning. (They always cook themselves or get take-out on weekends, so she has those free, and provide her with a car as well). In addition to her other daughter bein there rent-free, it’s a good deal. I know my brother and his wife-- if MIL becomes to frail to do what she does, they will figure out something else, but for now, it is win-win.
My SIL is Korean, and so my brother calls he the Korean word for MIL. I do as well, as that is what she asked.
My first cousins’ children call me “aunt.” Also, my mother’s first cousins’ kids, who are 20 years younger than me. In my family, a generational split pretty much dictates whether someone is aunt/uncle, or just 1st name.
31 is probably a lot different a lot different than 50. If my mother had been a widow and remarried when I was 31, my kids would have been 4 and 5, young enough for them to see him as “grandpa”. My kids are in their 30s now and based on them , I expect I needed some parental interaction in the form of advice when I was in my 30s and certainly I needed help with childcare. Maybe I would have referred to him as my “stepfather” even though he didn’t raise me- there’s no way for me to be sure.
If she she had remarried when I was 51* , my kids would have been their twenties and he neither would have been “dad” to me nor “grandpa” to my kids.
* whether she had been widowed/divorced for twenty years or one year and I suspect that makes a difference as well. My cousins will never call my uncle’s wife their stepmother - between the fact that the oldest were over 40 when he married her, and the fact that he married her 11 months after my aunt died, it will never happen.
My husband’s father had three wives. I refer to them as his mother, his stepmother, and his father’s widow.
He hated the evil stepmother who stole his father from him. It wasn’t until he was an adult that he really understood it was his father’s choice, not her actions. He never liked her, though.
We were close to his father’s widow, whom our children referred to as “grandma her-name”. She was invited to all the family stuff. But my husband never thought of her as a step mother, because he was an adult when she married his dad.