Each time this man cough, cat is trying to repeat it’s moves. It looks very cute. Cat wants to control his master. When the pet sleeps with you, it can keep you in its field of view. From all that the animal feels safe.
The most logical way sounds very simple. Our cats sleep with us because they love us, and thus show their devotion. And the last version says that the cats sleep with the owners, because the human body temperature higher than the temperature of other items in the house.
Don’t forget that Pets can easily change our bed to a place near the battery. But this cat thinks that man is not coughing, he communicates.