I (22F) recently went on a small family trip to celebrate my dad's early retirement. A family friend let us borrow their lake house but sleeping arrangements meant that I had to share a room with my sister (24F) and her husband (30M) in a room with two beds. They're newly weds who married quickly so this is his first time going on a trip with us.

I really didn't think it was going to be an issue because with the whole lake available to us, we wouldn't be spending much time in the rooms. The first night, there was no problem. The second night, my sister pulled me aside right before I went to go get ready for bed and asked me to change what I was sleeping in because her husband was uncomfortable. For context (this might be TMI and I am sorry) I am not a flat chested woman. It is quite literally the most annoying thing about my life and I am not sorry that I do not sleep in a bra!! That being said, it wasn't like I was sleeping in lingerie. It was just a big t-shirt, but because of how I'm built you could still tell I was bra-less. I've never thought it was a big deal but her husband is rather conservative (in like, all senses of the word).

I politely told my sister no because the only things I brought were A.) swimsuits, which would be even worse B.) a tight compression sports bra for beach volleyball, which I don't think is even medically advisable to sleep in and C.) a sweatshirt which I guess would disguise it more but it was hot and I didn't want to wear it.

She pressed me again and I said no again, pointing out that her husband slept shirtless. I don't actually care, but it seemed hypocritical to me so I said that if I am asked to find a way to cover up more (DESPITE WEARING A SHIRT), he should to. She got mad at me and said I was being ridiculous and staring at her husband (god, no. i would never) and kept raising a stink and trying to involve the rest of my family, saying it was a simple request and I must be trying to tempt her husband. I (loudly) fired back that this wouldn't be a problem if her husband wasn't staring at my chest, which prompted my parents to have me sleep in the couch on the living room the rest of the trip. I also made it a point for the rest of the trip to loudly call her husband out if he was looking too long at my chest in my swimsuit (which happened a couple times before he learned his lesson).

I didn't think I over reacted (I might've gotten a bit heated, but it was in line with my sister) but my family has kinda blamed me for ruining my dad's celebration by not letting it go and I can't help but feel guilty. AITAH?

ETA: If you are going to make a comment sexualizing me, don't!! It's weird and it's not funny.