Don't burn bridges.

Even if you think you are never seeing the other person ever again, keep the friendship and tie. For instance, if you were about to quit your job, it’d be in your best interest to not let off steam on your boss. You never know when you might bump into him later on in life or need a reference, then wishing you did not burn that bridge. Life has a lot to do with building connections and reputations - at any time you might seek assistance from someone you knew before in the past. Given, there already is a lot of hate and violence that really is not needed in this world. So there is no need to show those sides to those around you.