Ah, the thin line between love and hate.
Some cheaters become indifferent towards the betrayed, some become resentful and annoyed, and some even hate.
It's all part of their efforts to move on towards their perceived happiness with a clear conscience. Their entitled right to happiness and fulfillment that they feel you are either an impediment to, or a dead end towards.
They're deeply conflicted. They don't understand how they love(d) you and now want someone else. They know they're hurting you-deeply. They know what they're doing is incredibly destructive, irrational, fundamentally wrong yet, feels so right. So right they're compelled to do whatever it takes: give up children, destroy families, cause permanent trauma, jeopardize careers, futures, retirements, financial stability, reputations, etc. Mentally they're tearing themselves apart trying to make sense of what they're doing and why.
So, they make peace with themselves at your expense. They make peace with themselves and sense of their senselessness, allowing themselves to pursuit maladaptive compulsions borne from brokenness. They're chronically unfulfilled. They think fulfillment comes exclusively from others. They don't have the ability to seek individual healthful, diverse and wholesome forms of fulfillment, enrichment and self soothing. They turn exclusively towards a few unsustainable vices for fulfillment. They think a spouse is entirely responsible for their lasting happiness.
Demonizing your BS, rewriting marital history is an extremely effective way for the WS to justify their actions, make sense of the senselessness, move on and live with themselves. It helps pave the way towards their perceived happiness, retain some form of dignity, self respect and esteem with themselves, family and friends and, it works.
Some WS's take it one step further and spoil the shit out of the kids, buying their love and forgiveness while demonizing the betrayed co-parent in a relentless character assassination campaign. That too is very effective. They want the kids to understand why they cheated and sympathize.
That's the ultimate insult to injury.
The best and only things you can do to combat and survive this is:
-Retain your dignity
-Be classy. Be cool. Don't react to it at all emotionally. Respond tactically with class and maturity.
-Live well. Live a wholesome good life. Be happy.
-Move on. Control only what you can control.
-Protect yourself and your reputation-tactically, and tactfully.
-Get an attorney, listen to the attorney.
-Distance yourself, if able, from the toxins.
-Get a muse.