Sometimes no matter how well you treat your partner, if he/she has a mind to they will cheat on you. There's no way we can watch our partners 24/7, and who would want to? Sometimes people who already have flaws in their character that we did not see, change for the worse as the years go by. Wisdom does not always come with age for some folk. That's life. Nothing stays the same. Sometimes that's a positive thing and other times it's a negative thing. Nature has a way of keeping the Balance!