The scene:

Relationships between cast/crew members are fairly common. I met my girlfriend during a show, and we are currently cast together again. I can imagine how this could be a challenge for directors. I confess, a few times I've caught myself letting my closeness and allegiance to her interfere with the steady flow of the rehearsal. It happens, and sometimes you have to deal with it if the performers aren't aware of what's happening (which they may not be). But dont underestimate the maturity of the couple and their ability to conduct themselves in a professional manner. My advice would be to treat them as individuals and not as a single entity working against you. There's no reason they shouldn't return the respect you're showing them.

My husband and I formed our own theatre company after meeting while performing in a play together. I direct most of our company's shows and I treat my husband with the same respect and courtesy that I extend to all my cast and crew (he probably gets treated better during rehearsal then he does at home, ha). I insist that my husband audition just like everyone else and have not cast him in several role that he wanted because I felt there was someone better for the job.  Our company is small (5 board members and 10-12 regular ensemble members) and my husband and I do the lion's share of the work.  We try very hard to keep our personal relationship from negatively affecting the company.  However, it's partly our personal relationship that keeps the theatre going, besides we would never see each other if both of us weren't involved. Our company is founded on and thrives on family.  We have many spouses and couples who regularly work with us and haven't had any problems.  I think I depends on the maturity, responsibility and personalities of the people involved.