Nip this in the bud right now! This isn't the guy's first attempt at harassment (there is no other word for it) and it will not be his last. If you have a no-to

Nip this in the bud right now! This isn't the guy's first attempt at harassment (there is no other word for it) and it will not be his last. If you have a no-tolerance clause in your employee manual, fire the guy. If not, a serious discussion is in order and, depending upon how it goes, either the guy is immediately fired or is placed on double secret probation for some period of time. Explain that if this happens again, he's gone, immediately. No appeal. No reprieve. Seriously, you need to protect your company and yourself from these things. A seemingly minor event can go nuclear on you quicker than you could ever believe.