His behavior will never change! You know this is who he's been for all these years. Lying and cheating. Only you can stop this by stop allowing him to come over. This will continue for another 6 years and you deserve much better. Stop letting him manipulate you!
If you are willing to look at another person's behavior toward you as a reflection of the state of their relationship with themselves rather than a statement about your value as a person. then you will, over a period of time, cease to react at all. - Harbhajan Singh Yogi