Is it reasonable for relatives to ask couples to sleep in separate rooms when asking them to visit?

This is not a debate on if they have the right to, because they obviously do, “their house, their rules”.

So this is inspired from a a current situation im in. Me and my S/o are both young adults and have lived together for a while, since I was 16. We both have relatives in the same city so we go peiriodicly to visit them and usually get asked to stay with his dad and step mom. When we visit my S/o is told to sleep in his old bedroom, and I am told to sleep in the guest room. They are very well aware that we share a room at our home. They also aren’t religious. We always follow this but its hard because I have an anxiety disorder and one of my triggers is sleeping alone causing me to not sleep and even have panic attacks. We don’t push this rule since its their home, but my question is, is this a reasonable rule? Would you do this with your child? Would you protest if your parents asked this? If you’ve had this rule how did you deal with it.

I'd like to add, for my situation specifically I feel even weirder about the rule because his parents don't have the rule for my S/o’s 3 older siblings and their partners.

edit: thank you to everyone who has responded, I don’t often post personal controversies, and I get kind of nervous when I do. I know I have horrible spelling in my responses as-well so apologies for that.

EDIT 2: i doubt anyone will read this, but we talked to his dad alone, and his dad said that his wife was mad at my S/o (for multiple years?) for his career path and his dad hadn’t wanted to push her on the rule but once my S/o explained my anxiety his dad told his wife the rule was gone from now on. And for everyone who said it was that we were young, or unmarried, i brought both of those things up and he said it wasn’t either and that he was sorry. I told him i was pretty positive it wasn’t but i wanted to make sure.