Woman tells sister to cover up at her house; sister says no, 'It's my style.'

'AITA for telling my sister to stop leaving her room when she's wearing her nightgown?'

My 26, female, sister moved in with me 29, female, and my husband 32, male, days ago after her divorce was finalized then lost her job and was no longer being able to pay rent for her apartment.

We're mostly in agreement about everything except, I've been kind of having an issue with what she wears especially at nighttime when she unwind and tend to relax a bit as she says. I think that what she wears is inappropriate. She usually wear silky nightwear (nightgowns mostly).

She says that's just 'her style' and is what she's been wearing for years. Not just that, but she'd come out of her room dressing like that to grab water or use the bathroom. While yes, it was just me who saw her dressed like that I honestly could not risk having an argument with my husband over it. I suggested she buys some pjs but she said that she doesn't 'feel comfortable' in them.

Last night, I saw her in the kitchen grabbing something from the fridge and was dressed in a purple, strapped, knee length nightgown. I tried to speak to her about it but it didn't go well.

We started arguing and I ended up telling her to stop leaving her room when she's wearing stuff like that and she argued that there was nothing wrong with what she was wearing, that it wasn't like she was walking around naked or anything of the sort.

I told her it's my home and she's a guest and should just respect my request but she responded saying that just because she lives in my house does not mean that I have the right to control what she wears then stormed off to her room. We haven't talked since then and she is refusing to talk about it.

Edit: Here's the dress. It's not identical but close to what she was wearing, very close. Look at it and give judgement.

Here's what people had to say in the comments:

DogsReadingBooks writes:

YTA. She’s wearing a knee-length night gown. What next? She can’t show her shoulders? A little bit of cleavage? Her ankles?

infieldcookie writes:

She’s wearing a knee length nightgown to get a drink or go to the bathroom.

OP’s husband didn’t even see her in it so the argument isn’t even over something that’s happened… it’s unhinged to expect people to buy clothes they wouldn’t feel comfortable in when there’s nothing wrong with what she’s actually wearing, which she’s mostly only wearing in her bedroom anyway.

ExcitingTabletop writes:

I concur that OP is being overly controlling and has deep insecurities. OP has issues that she needs to address.

Zombified_Nightshade writes:

YTA. Don't take whatever issues you're having with your husband out on your sister.

TheLovelyMadamToh writes:

THIS. It's not her sister's fault she can't trust her husband. Purple and knee length isn't sexy lingerie. It's literally just normal evening wear.

Notes: Some people said it's like having a 'no shoes' rule, while other people said that's about hygiene, which this isn't. Some people also said 'it's my house, my rules,' where other's argued, 'sure, you can make whatever rules you want, but if they're ahole rules you're an ahole.'

Thoughts?