In all seriousness, it's also better not to over-honestize when addressing someone directly - IF you value the relationship, that is. What I mean by that is, vocabulary is important. If you want to preserve a friendship, you can tell someone you're upset with them or their behavior without calling them names or using the harshest, nastiest language you can find.

Unless you're ending the friendship. Then it's totally acceptable. (But don't do this and expect the person to stay your friend!)

/not directed at you