I just hope that he/she doesn't leave the F/O alone in the cockpit !
Since the Germanwings crash, a "no alone" rule has been imposed. If one of a 2-pilot crew needs to leave the flight deck, a cabin crew member must sit in during the absence - though not in a pilot's seat.
PS: See next post; what I said applies to one airline of which I have close knowledge - but I had wrongly thought that was universal throughout EASA-land. Thanks to wiggy for the correction.