In some cases, it's who is real to begin with?

Why not just worry about yourself staying real behind peoples back. ~ David Velasquez 

He who is not real behind your back was not real to your face. ~ Morris Goodchild 

Those that gossip about people behind their backs to you will also gossip about you behind your back to others. ~ Denise Hecht 

Isn't it amazing how nice someone can be to your face, but lookout when your back is turned. ~ Georgia Bower 

I know too many people that are back stabbers and untrustworthy, and will tell lies behind your back, covering their own arses. ~ Dee Arthur