Dont buy mattresses or beds for the other rooms,just get what you need and minimally furnish it. Im not proud of it but I have been thru something similar to your situation.
i dont want my husband to be ungrateful to his family because afterall they are his flesh and blood no matter how annoying they are so i indirectly initiate saving money so if no bed then people cant stay over right?
Stay strong and dont let in law issues ruin your marriage. Focus on all the love and stay as positive as you can!
Read more