A bully is another name for a coward. Bullies do it because it makes themselves feel better.....As long as they know it isn't getting to you, they will move on. Don't act like it gets to you. A simple reply is all you need to put them in their place. I promise you that all a bully is, is an insecure person with very low self esteem. Next time, just say, If saying/doing this to me helps your low self esteem, I am glad I could help.