Your employees are like your clients in the gym. They want to build their skills and strengths and hopefully, are able to do it on their own. If you're unable to manage your management, you are doing your employees and yourself a major disservice.
But you know what? The seriousness of the situation is your fault. Not because you were messing around with his girlfriend at the time, but because you did not prepare yourself and your business to accommodate the impact of this type of situation.