It's Just Not Worth It
I tend to ignore it, maybe because it's not worth reacting over. I think everyone at one time or another projects their own emotions on to someone in this way, eventually we all grow up and realize that everyone has their own life to live, their own woes and responsibilities. It's not only easier but more productive if you concentrate on yourself rather than waste time being nasty and bitter towards others. It's easy to get sucked into it when someone starts acting this way towards you...it takes patience and perspective to ignore it. Let them waste their energy thinking up ways to be cruel, that's on them. Live life on your own terms.