Erm, if the child wants someone to blame, why should the innocent parent shoulder that blame?
Even if there are relationship problems, that is not a reason to cheat. It might be a reason to go to couple's counselling, and individual counselling, it might be a reason to end a relationship (though that should be thought long and hard about, and not done UNTIL couple's counselling has been tried unless one partner is abusive), but it is unequivocally NOT a reason to cheat. Because there is NEVER a reason to cheat. NEVER.
And in the case where Mummy kicks Daddy out because Mummy had an affair - MUMMY should be the one to leave. If she couldn't put her DC's above her own sex life, well, she's not much of a bloody parent, is she.
It's just selfishness and self-absorption that causes people to cheat. They DON'T put their DC's future well being as their top priority when they decide to tear their family apart by choosing to have an affair.
And IMO, that is selfishness, thinking of themselves and THEIR emotions and what THEY want ABOVE the emotions of their DC's, and what their DC's want.
I HAVE been in a position where I could have chosen to get involved with someone whilst already in a relationship. I chose to back well away and not get involved, and to work on my relationship instead. Because how my DC's would have felt knowing that I had chose my own feelings over theirs was enough to stop me from even meeting with this person, because oddly enough, I put their future well being over getting a shag from some random.
Who a few years later ended up not being 'some random', because we bumped into each other a year after my marriage had been blown apart by my Ex-H's cheating, and got into a relationship then.
I just can't understand why a parent doesn't consider their DC's feelings BEFORE embarking on an affair. And I then can't understand why that parent seems shocked that the child is angry with them, hates them, or even wishes them and their new parent dead to them. Why do that to your child?!