Do You Defend or Stick Up for Others?

If you would, under what circumstances would you do so?

If you have done so, please tell us briefly about the situation, like what was being done to or said about the person that caused you to feel the need to defend them?

I'm asking, because I feel sometimes that some of my friends should have stuck up for me when someone was being mean to me and none of them did. It hurt. I am wondering if I expected too much of them, or what?