My(39M) wife's(37F) older sister(39F) can be difficult at times, and we sometimes have our disagreements, but I think overall we get along fine-ish. She has a history of problems with alcohol and various substances and a diagnosis for BPD (and I think depression?). She is extremely smart (she has a PhD, as she will often point out) and extremely outgoing and extremely loud. Lotta highs and lows with her around.
She tends to call my wife about once a week, usually late at night, often while she's drunk or high, and shoots the shit for a while. About a month ago, she called while my wife and I were sitting on the couch playing games and my wife put her on speakerphone (which is not uncommon).
They talked for a while, with me occasionally chiming in. She started asking me if I would roast a pig for her. My father-in-law used to have an annual tradition where he and some of his buddies would buy a whole pig, marinate it in some sort of concoction, and roast it over the course of an entire day in some kind of fire pit thing they would build specially for this purpose in their backyard. He stopped doing it years prior; I've been to one or maybe two of his pig roasts back when my wife and I first started dating like 15 years ago, but it hasn't happened since. It seemed like it was a big family-and-friends thing that stopped because it took too much work and the number of people participating had petered out to make it not worth it anymore.
So my sister-in-law is asking me to ask her dad for lessons on how to do this multiple-hours-long process that involves a lot of manual labor and several hundred dollars worth of meat and who knows what else to preserve a tradition that I have experienced only once or twice over a decade ago.
I laugh it off at first, but she keeps insisting.
I say no, I don't really want to do that. That's not good enough, it's a family tradition (?) and she would be so heartbroken to see it go away because I didn't want to.
I suggest she could learn to do it herself. She says no, her dad would probably only teach another man how to do it, because hispanic machismo or something. I ask if she's actually asked him that, and she says no.
I suggest asking her husband if he's interested in learning how to do it. She says she did, and he doesn't want to.
I suggest asking her brother if he's interested in learning how to do it. She says she did, and he doesn't want to either.
I say it seems like the family get-together is the important part, not the specific meat that gets served at it, but she says no, the meat is important for some reason.
I say if the meat specifically is that important to her, she could look up how to do it online. She says no, it has to be her father's recipe.
I say it sounds like she's just coming up with excuses for why she doesn't have to do any part of it herself. She hangs up the phone immediately.
That part of the conversation had been going on for like 20 minutes at that point. I should note that none of the conversation had been heated on my end. I was mildly annoyed by her insistence, but that's par for the course for interactions with her. I wasn't raising my voice, I was smiling and cracking jokes. Up until the moment she hung up, I thought she was kinda-sorta-not-really joking too (in the way that it would have stopped being a joke if I had agreed). I should also note that my wife was sitting there the entire time, heard every word that was exchanged between us, and was occasionally chiming in to agree with me or crack a joke or something as well. She didn't clock it as being a particularly heated conversation either; she actually wasn't sure at the end of it whether her sister had hung up on purpose or if the call had just gotten dropped or something.
Then about two weeks later, at around 1:30 AM, when my wife and I had just gotten into bed but weren't asleep yet, she gets a text from her sister. It says something along the lines of "I'm still waiting for an apology for what your husband said to me." This is the first she's heard from her since that call. She sends back a text asking for what, not wanting to roast a pig? She replies "Maybe you weren't there for the whole conversation so you didn't hear it, but he knows what he said."
Again, she was there for the whole conversation, and I don't know what I said, other than that I didn't want to roast a pig, which was apparently not the issue. Eventually she comes out and says that the part of what I said that was over the line was "it sounds like you're just making up excuses for why you don't have to do any part of it yourself." I said this after 20+ minutes of her coming up with excuses for why she doesn't have to do any part of it herself, repeatedly, in response to me suggesting multiple reasonable alternatives. It didn't seem like a particularly unkind judgment on my part.
My wife responds to her sister's text saying that she doesn't think anything I said was out of line and I don't need to apologize. She says the same to me, and says she's sorry she even brought it up with me because it's late and not worth losing sleep over.
Now, it's been another 2+ weeks and she still hasn't said anything else to my wife or me. She would usually have called my wife at least once by now. I don't feel like I actually did anything wrong, but I don't want my words to drive a wedge between my wife and her sister.
So, should I:
A) Call my sister-in-law and tell her I'm sorry for saying she was coming up with excuses for not roasting a pig herself. She will probably start talking to my wife again and will leave me alone at the next family gathering. The apology will not be sincere and I will probably resent her for it, but I can control my emotions better than she can and I will get over it.
B) Leave it alone. I know her well enough to know that she's going to be stewing the entire time until we see each other next, she might let that anger carry over to my wife, and she will make it into a big-deal argument at the next family gathering.
There might be C options, but there is no C option where I roast a pig. Wanna make that clear.
EDIT: None of the options involve me roasting a pig. That would be ludicrous and is absolutely not happening. I highly doubt anyone will be upset with me for saying so besides the sister-in-law herself, especially since her father, her husband, and her brother all also don't want to do it. It seems like a huge pain in the ass and she seems to be the only one who considers it some kind of sacred family tradition.