When I was at the UA Crew Desk in 1999-2000, we had at least one pilot couple that flew together on every trip, did PCs together, did everything together.
It had been that typical day from hell in the NYC Area, and I was trying to move up a crew to fly an earlier JFKSFO 767. Protocol was to call the captain, then the CA will notify the rest of the crew. I had called the layover hotel for hours, at the time the Helmsley, left messages in the Captain's room to no answer. Before my shift change I tried one more time, called the front desk, and asked to be put through to the F/O's room.
Me: Hi is the F/O YYY? This is XX from the crew desk and I have been trying your CA for hours but no answer. I need to notify you of a crew move up for tomorrow.
Her: He's in bed with me."
!!!
Only then did I notice their last names were the same, and looking their calendars, every trip, every PC, was flown together.