I had a son-in-law that is one, as much as I believe in marriage forever I was so happy when my daughter finally saw right through him and got him out of her life. He was so messed up, lies, lies even when the truth was better. He also had some cult like way of controlling her when they were together. They can be very convincing at times- suck some people right into their web of craziness.
I pray for you that your son will wake up, we became convinced our daughter never would- but one day she came to her senses.
I believe it was on Nancy Grace last night where it was said that a mother had seen the same thing in her daughter and got the child away from her.