A shared room needs shared expectations before the first night.

Most conflict between people sharing a space is not about values; it is about defaults nobody stated. What time the light goes off, whether the window stays open, how loud is normal in the morning: each person arrives with an answer they have never had to say out loud. The disagreement then feels personal, when it was only unspoken.

Have the boring conversation on the first evening, before anything has gone wrong. Sleep, noise, tidiness, guests, and what to do when one of you needs an exception. It takes ten minutes and it is much easier than the same conversation on night four.