Got reminded of a story I heard some years ago:
A British TV channel was doing a documentary about "primitive" tribal people. They invited some people from Papua, from a tribe which had had VERY little contact with the outside world, and three men agreed to come.
When they arrived to the UK, they were all given hotel rooms, all the usual courtesy etc.
At some point one of the tribals asked (via a translator) if they were being punished for something? The TV channel people were obviously surprised and worried by this, they certainly hadn't intended anything like that.
They asked him why he thought that: It was because they were all put into separate rooms. This again surprised the TV people, they just explained that they thought they like the peace and quiet of having their own rooms, as is usual in the west.
But the tribals didn't sleep like that. They all just kinda cuddled together in big groups. They were thinking about stuff like "but what if someone has a bad dream, and wakes up all alone and afraid?"
This has been for me both a heartwarming thing (these were grown, adult men, worried about each other in a very direct way), and a thing to keep in mind when the whole "sleeping together" idea gets brought up: Humans for a huuge part of their history slept in much closer quarters than today's isolation. Even many beds made for kings and queens (or other aristocrats) had pull out beds that were used by their servants, who slept in the same room (the main bed being covered by drapes). And there were some inns famous for having massive beds that could fit a bunch of people, and it wasn't all just about having orgies...