Sleeping?

You wake up in the middle of the night. This is unusual. Something must have happened to wake you up. You fling your arm across the bed, to comfort yourself in the presence of the person you're with. They comfort you, but can be a prick sometimes. They are fast asleep. You don't turn around; you don't want to wake them up.
Then, you hear someone in the toilet. Weird, you and your partner are the only people in the house. You notice the window being open. It was closed when you went to sleep. But no matter, it's a second story window. Nothing can get in.
Then, you hear the sound of your partner coughing in the hall.
You turn around.