AITA for not letting my sister, her husband, and their kid stay with us because she wants our bed?

I (29f) live with my husbands (32m and 29m) (we're not legally married but we are in every other sense so we use husband/wife) in a 4 bedroom house. Our bedroom contains a super king sized bed. There are 3 other bedrooms, each with a single bed. 2 for my kids and 1 for 32's son.My parents' birthdays are within the last week of October, which is a school holiday. My sister will be coming to see them, along with her husband and their daughter, and my sister is 6 months pregnant. They live nearly 10 hours away from us so they only come see us 1 or 2 times a year.A few months ago now, probably May or June, my sister asked if they could stay at our place during the week of mum and dad's birthdays. As mine and 32's kids will not be with us during this time (50/50 custody), we said they could stay.They're meant to be coming next week. They've booked time off work, and called to tell me. However, on the call I said something about changing the sheets before they get here, and my sister said that she could get her husband to help me change the sheets on the "big bed". I asked why we'd be changing the sheets on the "big bed" and she said she wasn't going to sleep in our dirty sheets.In the initial phone call, we agreed that she, her husband, and her kid would take a single bed each, and I brought this up, and she said that we had said that initially, but she's now pregnant and she needs to share a bed with her husband. I then said that if she and her husband are in our bed, and her daughter is in another, then me and my husbands only have 2 single beds for 3 adults, and she said that one of my husbands could sleep on the sofa. I laughed at that one and said she's not having our bed. She said I was being unfair and she clearly needed the bed more and I said "keep talking and you can get a hotel". She then tried again and I wished her luck finding a hotel that could have them for a week within her budget. She called me a bitch and I hung up. She's since been non stop calling me and my husbands to ask me to reconsider, but I'm not answering.My stance, which 29 agrees with, is that she's taking the piss, she's changed the terms of me letting her stay here, and I'm not making someone sleep on the sofa for a week to appease her, especially as I'm not even in touch with our parents and they're the main reason she's even coming here.32, however, feels that it makes sense to give the pregnant woman the bed and all she did was ask, and has even said that he would sleep on the sofa for that week as he wants me to have this time with my sister. He's also said that he feels I was a little quick to snap and as he's willing to take the sofa there should be no issue.AITA for uninviting my sister? via /r/AmItheAsshole https://ift.tt/2Hb4Ha5