Sooner or later, management has to limit this. It has the potential to:

A. Black-list certain captains and FOs
B. Create dissention in the cockpit when it becomes known (and it will)
D. Make Scheduling tear out their hair
E. Allow 'crew feelings' to run the airline

The concept of not pairing people who can't get along may improve CRM in the short term, but it undermines the professionalism of the pilots in both seats.

What were they(mgmt) thinking? Where's the union in this?