Don't feel guilty.
Remember that you're not to blame for someone else's passive-aggressive behavior.
Refuse to play their game.
Because a passive-aggressive personality doesn't know how to respond appropriately to conflict, he or she will most likely deny everything. It's important to express your concerns and anger, but stick to the facts at hand and how his or her actions make you feel.
Confront their dishonesty.
Not confronting the passive-aggressive behavior will only reinforce it. Confront the person immediately and let him or her know you are confused by the behavior. If they value the relationship, he or she has to stop the behavior.
Don't let them get away with bad behavior.
Instead of letting the person off the hook and allowing him or her to continue the behavior, try to create an atmosphere in which he or she might feel more comfortable sharing feelings of anger, resentment, fear, etc.