In my opinion they lie because they think something like.......let see if I can pull the wool over this one/or this time.
How much can i get away with?
I deserve to do what I want to do with whoever I want to do it with....SO what she/he doesnt know wont hurt her..........and if its found out....Then I come up with another lie.....
Im smarter than the rest......I can fool ANYONE.......
I have to say/do whatever it takes.............to get whatever I want.......
These type of people will never be able to have a loving,open, and honest r/s with ANYONE ........they are disordered.......and this usually never changes.......best thing to do is not to even question their actions or motives...........its all about THEM, whatever step they take.