The TV shows had to follow a code of morality back then and they were not allowed to show/suggest male and female in the same bed.
That being said, in reality, houses had more people in them then (more kids) and there wasn't even an opportunity for parents sleeping apart, hence the saying "in the dog house".
This makes sense, thank you.
The intention of my original comment was only to offer a lighthearted observation, followed with a question about said observation.
Not sure why it became such a point of contention.