Lawyer is good advice. If it's not acceptable in the company then you should tell him to leave. If you don't you poison your culture. The employee now knows

Lawyer is good advice. If it's not acceptable in the company then you should tell him to leave. If you don't you poison your culture. The employee now knows that she will still need to "deal with" harassment at this organization. Her outlook on the company culture will be forever changed. And she will share this experience with her friends and potential recruits forever. Likewise the harasser will know that there are not serious consequences for unacceptable behavior and will continue to "get away with" things. He will repeat the behavior among his friends and towards future staff. They may not have the confidence to report it. This is one of the root causes of the gender imbalance in the work place. Harassment is never ok. This needs to be explicit and you should work hard to build a team where there is complete trust that violations will not occur.