Pinkee here~So, you’re in a relationship with a compulsive liar. Damn. I hate when that happens. What to do?
First of all, I would evaluate how deeply you are in. Is this someone you just started seeing? Or, is this someone you feel strongly committed to, whom you may even have one or more children with? If this is a new partner, you may want to seriously consider cutting your losses before you get too deep, and moving on. If not, and depending on the seriousness of your feelings and commitment, you may want to hang in there and see what can be done.
Also at this time evaluate the seriousness of the behavior. Some compulsive liars tend to lie about things that don’t have much importance in life. Others may be involved in serious crimes (including possible murder of previous partners) or things such as cheating that you find absolutely unacceptable. Generally, the less serious the behavior, the easier it is to change.
Another factor you will want to consider is whether your partner seems to have any remorse for her (or his) lying. A lack of remorse is a bad sign, and one that indicates a poor prognosis for the ability or desire of the partner to change the behavior.
If, after considering the above, you realize you want to try to save the relationship, I recommend professional help. See if your partner is willing to seek the help of a life coach or therapist, whom you can attend the first session with and perhaps periodically other sessions as well. This will enable her to address the underlying issues that caused the behavior in the first place. You will also need someone to see as a couple, to help you negotiate the terms of your “new” relationship and to rebuild trust if your partner shows herself to be willing and able to change.
While I am not a pessimist by any stretch of the imagination, I have to give a word of caution here: I have worked with people who have been able to change this behavior, but in general the outlook is poor. If, after giving it what you consider to be a reasonable amount of time and effort, your hopes of a successful relationship are waning, do yourself a favor and move on. You deserve to be treated honestly and respectfully. However, if you ever expect this to happen, you must start by being honest with YOURSELF and treating YOURSELF with enough respect to get out of a bad situation.