I appreciate what you are saying, and I agree. I don't need permission or approval from anyone to live my life as I see fit. But as someone who has experienced being asked to do things differently because of who I am or my relationship, it doesn't feel good to be disapproved of, especially when it comes from parents or in-laws. I guess it's nice to have their approval because I love them and they have my 100% approval no matter what they do or what they believe or how different we are from each other. I can move beyond anything they may say or do or believe because they are my family and I would do anything for them. But it's nice to get what you give, so if I give that to them, I would hope that they give it back (and they do).
Personally, when I invite someone into my home, they are my guest, and I want them to feel comfortable. If they sleep together, fine. If they would like to sleep apart, fine. If they would rather get a hotel, fine. That's just being a good host. And I can always choose not to host someone in my house if something about them staying in my house in the way they would like really bothers me that much. If it's my problem, I'm not going to impose a solution that requires THEM to make the change. And maybe couples don't mind sleeping apart. But not everyone is going to accept a request or a rule like that without thinking that the host has a problem with them or their relationship. And maybe you've never had that problem in your family or life. If so, that's awesome! But for a lot of us that hasn't been the case.
And I guess we can just shrug it off and ignore it, but it still feels uncomfortable when people wouldn't want me and my partner to sleep in the same room for whatever reason.
I can see we don't agree, and that is totally fine. I'm glad we can discuss this respectfully rather than it escalating. It's your house and you can choose to do what you will.