153:8 When a woman is a niddah, she and her husband may not sleep in the same bed. This is true even if it is not her own bed, even if each one is dressed, even if they are not touching each other, and even if each one has their own mattress. Even if they are in two separate beds, if the beds touch one another, it is not permitted. If they lie down on the ground, they should not lie facing one another unless there is significant distance between them.
Similarly, if they are sleeping in two parallel beds close to one another and facing one another, even though there is a space between them, there is reason to prohibit this unless there is a significant distance between them. The husband may not even sit on the wife’s bed, even when she is not present. She is not permitted to sleep on his bed but we are not strict about her sitting on it.
153:9 They are not permitted to sit together on a bench that will move unless another person sits between them. They likewise should not travel in the same wagon or on the same boat if they are doing so just for a pleasure trip. If they are traveling on business, it is permitted even if they are by themselves provided that they sit in a way that they don’t touch one another.