If the working relationship is causing tension at home, the couple should look at ways to shift work responsibilities or change the reporting structure.
Labour and the trade unions have noted the tension between relaxing laws that limit working hours and the professed concern of David Cameron, the Conservative Party leader, with people's work-life balance.
In their 30 years together, they have not publically displayed strife or tension, and conflict does not appear to be an inherent part of their working relationship.