Relationships breaking down are messy at the best of times, toxic at their worst. More people than not, when faced with the collapse of a relationship, will act like a 13 year old than a rational adult.

If the company is seen to have encouraged or even acknowledged the relationship it can create a huge liability, especially if one of the people involves feels like they got stiffed because of relationship issues (sidelined, transferred, had to resign, etc).

The number of couples who say they met at work suggests that blind eyes are often turned, but a company has those official bans on intra-office dating for good reason.