I know what its like…my cousin has been a chronic liar ever since she was a little girl… One of the posters said it had to do with low self-esteem and I tend to agree.
The final straw with my cousin was when she lied about my uncle’s tombstone… When my uncle died it was the raining hard for about 3 days straight in the central part of Puerto Rico and the ground was too soft to put the tombstone in place. The funeral director told us that we had to wait for the rain to stop and the ground to harden up so that they could put the tombstone in place… My family and I tried staying longer in Puerto Rico but financially we couldn’t manage it and so my cousin was asked if when she went on vacation to Puerto Rico the following month if she would handle making sure the tombstone got put on my uncle’s grave.
For me this was a big mistake but since I did not want to upset my mother in arguing about it I let it go… Anyway, zoom to a month later and my cousin calls my mother from Puerto Rico. My mother naturally asked her if she had gone to the cemetery and got the tombstone put in place. My cousin said yes… my cousin’s brother who lives in Puerto Rico then got on the phone and for some reason my mother asked him the same question and he said “no”…
This made my mother furious and she hung up the phone… My mother cried so hard afterwards…

My uncle was her baby brother who she raised single-handedly after her own mom died when she was 7…so my cousin’s lie cut her deeply… and it was tearing my mother up that she could not get the tombstone put on her baby brother’s grave…
Suffice it to say my mother cut off all contact with her and so did I… Sometimes people are just too toxic to be around and won’t change unless they make the decision to do so…
The best advice is to keep conversation topics with chronic liars about general things like the weather…
God bless