To be annoyed DH is tracking his sister's pregnancy

[lizzidripping]

I am due to give birth in January. DH keeps forgetting the due date and doesn't know what week of the pregnancy I'm on.

His sister is due to give birth a few months later and he's put a weekly event in mine and his shared calendar.

This is our second pregnancy but does it mean you should be this level of checked out
.. I can guarantee you he doesn't even know what day of the week ours even falls on to put this pregnancy in a calendar.

When I was pregnant with our first his sister barely paid any attention and I think visited DD maybe 3 times ever since she's been born (she is now nearly 3).

Relevant backstory - when we dated and got married DH'a sister was always a bit rude and difficult with me. Examples include letting herself in to our home with a spare key she had and refusing to give it back, stripping down to her underwear in front of people at our wedding (she wasn't drunk), inviting herself over and then not showing up without saying anything, crying at family events that she pressured DH and I to host (ie. in our home) and making a scene in general. For the record, I am always polite and kind and don't rise to the drama.

AIBU to feel annoyed DH is putting this much importance on his sister's pregnancy?8

I just asked. He said it came about because he wanted to know if she knew the gender so we would know whether to charity shop DD's stuff or hold them back for her. We're having a boy this time and don't plan on having more.

She told him when she would find out and that's how it went about being in the calendar.
I believe SIL and her husband's income are not great (charity sector and temping) and could definitely use the help. This will sound hideous of me... Where I've been very happy to give DD's stuff to others, I sort of don't want to do that for SIL. But I will have to because if I didn't it would be too unkind.

Ah, glad there's an explanation.

WHY was she walking around in her underwear at your wedding?? Please please share more of that story.

This makes sense and makes it a lot less weird!

Re the clothes.
I'd view it as you are doing it for the child not her iyswim.

Also after age 3 there is a lot less in the form of hand me downs as everything gets more wear and is wrecked towards the end anyway.

I'd also feel free to hold on to sentimental stuff or things you love and also to give some things to others of stick them on vinted ot obliged to give every scrap to them.

I don't really know because I wasn't there when it happened. Guests, the wedding photographer and my sister all told me after the wedding. Something about her being uncomfortable in her clothes so she took off her dress out of annoyance. But it happened where everyone was milling about as opposed to toilets or something.

The only reason I link it to her possibly doing it out of revenge or spite is that it was a bridesmaid's outfit. Which I also said she didn't have to wear if it was uncomfortable. And I very much only did it because I felt like I had to include her as one. Otherwise I would honestly never dream of telling her what to do/wear etc. And so as not to drip feed - it was a sari as I come from an Indian culture (and that's what everyone else was wearing) and the outfits were paid for by me so nobody had to buy something they wouldn't wear again. But also to get into your undies within an Indian culture is pretty taboo and so I do think part of it was out of spite.

Whaaat? She sounds like a grown woman with the mental capacity of a toddler.

edit: I posted this before you updated with more context. That further explanation makes more sense. But still quite childish!

And so disrespectful to remove her sari. Bonkers!

I think she sounds vulnerable rather than spiteful because the social mistakes she is making are so stark. Spitefulness would take a more covert form, usually? But she doesn't seem to mind others seeing her stripped down to her underwear at a wedding, nor others at a social gathering perhaps being aware that she would happily have taken all the children's party bags at a party for children. This sounds like the problem may not just centre on the conflict between the OP and her SIL.

Well, he's oddly overinvested in his sister's pregnancy and that would irritate me for sure.

What I really can't understand though is why you are at pains to be kind and polite to his sister given the way she behaves? I wouldn't be.

Why does she have a spare key to your house? I'd get that back sharpish and if she wouldn't give it then I'd change the locks so that her key wouldn't work. I really wouldn't care what sort of a tantrum she threw over it. She hasn't been at all respectful of you and her behaviour is awful.