These things may happen because you have to stay in bed so long.

The next morning, all she wanted to do was to stay in bed.

"You really believe your father's going to pay me to stay in bed with his daughter?"

But he said I should stay in bed and rest for a while.

He's to stay in bed for the rest of the week.

But she couldn't very well stay in bed all day.

She could see no reason for him to stay in bed.

What if I were to stay in bed all morning?

I think you should stay in bed for a week or so.

Then he has to stay in bed for a week.