It is a very risky business. Other employees may end up resentful and there will be a drop of productivity if so. Likely you will treat her differently than the others such as giving her information that she in her current position should not have, refusing to see her performance problems, etc. Likely she will act differently, letting others know she is privileged and that they had better not disagree with her.
I have worked several places where the boss was dating one of the employees and in two out of three cases, it was a cancer in the workplace. In the third case, the couple were able to totally keep their relationship out of the workplace but that meant no displays of affection (or worse closing the office door and having sex where the other employees could hear you), no special treatment in favor of the employee(in fact her promotions got held up and she was held to a much higher standard than the rest of the team), no insider information, and no acting as if you were more important because you were having an affair with the boss. In the worst case, the company lost several valuable employees because they couldn't stand to be managed by the secretary the CEO promoted to be the Project Manager because he was having an affair with her. In the end she lost her job too because he married someone else.
Ok let's be blunt and share some of the negative consequences I have personally experienced or observed form bosses dating their subordinates:
- I have seen people promoted over qualifed people to jobs they were
neither qualified for nor good at.
- I have seen an unsatisfactory performance appraisal (which was
well-deserved) be changed to an Outstanding
- I have seen more qualifed people quit rather than work for the
unqualifed person promoted over them
- I have seen a co-worker flash her sexual parts in a meeting after she
and the boss had had a fight. To say this made everyone else in the room uncomfortable is a mild understatement.
- I have heard them having sex in his office during nwork hours which
made for very uncomfortable meetings later on the same offce.
- I have seen a subordinate who had no business knowing about a
performance issue with another employee, come to work and brag about
how she knew and how much trouble the other person would be in.
- I have seen bad suggestions implemented becasue they came from the
person who was in the relationship even though all the entire rest of
the staff objected to the decision. BTW some of these decisions lost
the company a good deal of money.
- I have seen the entire staff complain to higher managers about a
problem which the couple involved vehemently denied was happening. The couple almost always thinks their relationship is causing no issues whatsoever.
- I have seen the workplace become absolutely toxic when the
relationship breaks up until the subordinate finds a another job or
is fired.
- I have seen clients be appalled at the unprofessional behavior a
person in a relationship exhibited in front of them and the manager
not care to fix the problem becasue it would disrupt his social life.
If you truly want a relationship with this person the best thing you can do is find him/her another better job in a different company before you start.