One of the most difficult things you will have to do as a leader is to handle uncomfortable situations with employees.
Talking to an employee about their behavior is hard. Terminating people is probably the hardest thing you will have to do.
All of the hardest things you have to do at work, and in life, involve people. Decisions about products are easy.
Unfortunately, too many people don't deal with the hard things. By letting it go, you are making your life harder. And you are not doing any favors to the other person either. By not dealing with the situation, you are holding them back from improving their life.
When difficult situations happen, a tough conversation or even termination, it won't feel good but you shouldn't feel guilty about it.
Remember, if you don't deal with the situation it will only get worse. These things don't get better on their own.