My 24 year old daughter is engaged to a fellow who I am afraid is a pathological liar. It started with exaggerations, then it turned into small lies. Now he is telling big out and out lies about my wife, that are driving a wedge between her and my daughter. My daughter has strong feelings for her fiancé, and we are caught in the middle here. We do not have much influence over her, as they are living together. Do we confront her with the fact that she is engaged to a pathological liar, or do we have to go through with the wedding and let her find out for herself? We had planned on a big wedding in July, and now we are considering cancelling all of the plans we have made because we don’t see this marriage as being viable. We would like her to realize her mistake now and avoid making a huge mistake marrying this guy.

I don't think there is much you can do.

If it were my daughter, and who knows, in 15 years, it just may be, I guess I would talk to her, explain my concerns. But in the end, it's her decision. I guess I would back her and hope for the best.

No matter what, I'd always be there for her, even if in the end, it doesn't work out.

My mother tried to get me not to marry my ex wife, but I didn't listen. But in the end, when she walked out on me to be with every Tom and Harry, my family was right by my side.

I agree with andrew. There isn't much you can do but express your concerns and possibly suggest that both of them see a counselor before the big day... maybe even as a family? In my opinion, the worst thing you can do is bail on her and not support her to the end. This will create deep wounds and worsen the already rocky relationship between daughter and mom. She's an adult and if this ends up being a "mistake" then she will learn from it.

She IS old enough to make this decision.

On the other hand, I am sure you don't want her to be in (what you consider) a bad relationship.

How about asking the future son in law out for breakfast and confront him?Communication being the key here,how does he know you think this way about him,how would he know you know he is this liar?

If you want her to be happy and solve your problem,I believe this is a viable solution.

Remember,he won't take it too well,there might be a separation from you two for a while,heck,you might chase him off,maybe you should do it!

I agree with the others love is blind and even if you get her to see he is lying most likely she will be in denial and make excuses for him. It could make her take his side and get upset with you but it may be worth trying. Sometimes hind sight the one that was so blindly in love will ask why nobody said anything. So at least you would be able to state that you did try.
I am not so sure how good it would be to back out of the wedding plans but maybe cut back where you can without it causing too much hurt feelings. When you offer something it is usually not meant with conditions unless stated up front.

Well, you can respectfully protest this engagement, yet still attend the wedding. You can even try talking to the boy I suppose, but if he's real arrogant, it will probably just make it worse.

A good heart to heart with the daughter is in order.

And a good talking to with the man is in order too.

"You do this, fine, but should you hurt her, be warned, they will never find all the peices of your body"

Typically a pathological liar is a very insecure person. Tell tale signs are control issues (of your daughter), and isolating the 'intended' from family and friends. There is a pattern of behaviour that usually increases with any interference, and because they are charming and believable, they force a 'them' or 'me' situation, which only furthers the family divide. I would seek the advice of a counsellor on your own to get a better understanding and direction in how to proceed for your daughter's sake. Additionally, when lies become apparent, for now, jot this down in a diary of some sort to talk to a counsellor about. He/She will see the warning signs and will advise you. I would not just let this happen without being better informed on what you are dealing with. You can probably confront him until the cows come home, but his behaviour will not change. It may be more of a situation where your skill will be needed when she realizes herself that it is not a healthy relationship.