Don’t retaliate to a backstabber. Picking a fight with backstabbing coworkers is the worst thing you can do. By stooping to their level, you will be perpetuating the drama. If one of them has the nerve to talk to you directly instead of just gossiping behind your back, don’t give them anything to use against you when they return to their gossiping mates. Maintain eye contact, speak in a level tone and then excuse yourself politely by saying you have a deadline. They will walk away with nothing and you’ll have scored an emotional victory for yourself.
Source: work.chron.com/emotionally-deal-backstabbing-coworkers-gossip-office