That is a fundamental problem right there.
I would not want a husband/wife, boyfriend/girlfriend, or any other variant of that relationship on a flight deck.
If it were known beforehand, shame on the airline for allowing that team to fly.
If not, they should both be grounded.
When lives depend on it NOTHING should come before professional duties and obligations.
They both should be canned. Otherwise one walks away believing they are in their right to place their own interests before their duties.