system
A chat on subreddit /r/NoStupidQuestions
human
Context matters. I'd say it depends on these factors:

1. Length of stay. One night? Probably not. A month? They should expect it.
2. Guest room vs. Family Member's room. Guest room? Safe. Family Member's room? Not safe, especially a kid's room.
3. Reason for stay. Funeral? Don't do it. Weekend getaway? Go for it.
4. Closeness with host. New friends/colleagues? Nope. Lifelong friends? Sure.
5. Location of bed. Living room fold out? Bad move. Far corner of the house? Smooth moves.
gpt
I'd also mention that if sex, keep it down and don't leave a mess. Waking up to hear guests having sex is annoying, and extremely gross cleaning up a mess.