The female HR Manager dates and later lives with the VP of Sales. She tells him everyone's salary and upcoming promotions. He's a blabbermouth. Pretty soon the whole company is up in arms. Certainly we have to face the fact that the workplace is now the place where we often meet our significant others.
Employees are younger on average, and marriage takes place later.
That's probably as effective as the war on drugs. If the examples above don't scare you, then by all means, leave things as they are. If you want to prevent a problem, however, then establish the fairest policy that you can. Well, start with being discreet. Or perhaps, just perhaps, the company will accept the relationship if you are open about it, have a strict working relationship while on the job, and do not have a reporting relationship.