What I had in mind was more to the effect of say, there's a group of four friends. One of them is a manipulator so she lies to one friend to get another to do or not do something... Or she lies to two of them about the same thing trying to turn them against the fourth as a means of controlling that fourth friend, because she's not going to go away.

How to you bust the liar? How do you make the others see and understand that she makes a big deal out of nothing by lying and when she doesn't get the desired effect, she lies again but to the closest friend enlisting their help.

Is that clear enough?