Legally speaking, in most states an employer can enact a policy that prohibits employees from dating one another. Prohibiting it could decrease morale and could even result in losing employees who wish to date coworkers but cannot. In practical terms, it can be incredibly difficult to enforce, too.
Do you have to declare a relationship at work?
Employers can tell employees if they begin a workplace relationship they must tell senior management or the HR department. The issue is, and should be, one of whether the relationship creates a genuine conflict of interest and/or leads to conduct which is, in fact, prejudicial to the employer.
What kind of relationship should be between managers and employees?
An important part of your job as a manager is to provide your employee with frequent guidance — as well as with the necessary challenges and opportunities to support their ongoing growth.