A man was working the night shift when he received an urgent phone call, giving him information that caused him to dash home at breakneck speed.

On bursting into his bedroom quite breathless he found his informant was quite correct. His wife was in bed with someone he had never seen before.

However, far from being angry, he greeted them both with a smile and a few hours later brought them both breakfast in bed.

What is the explanation for this odd behavior?