Is it okay/normal to say mean things to someone's face because they rejected you?

This may seem like bait, but I'm asking a genuine question. This happened to my girlfriend where she rejected her former best friend (in a nice way…

Well, this Conservative guy (I’m also Conservative) asked me out after I lost feelings for him the year before. He proceeded to call me the N-word and a libtard. Since those are both slurs, I think they’re wrong.
Conservative women trying to date after the age of 13 always give me a chuckle.