So there are multiple sides to this question
As a step parent for me... Enough was when nothing I did was good enough, DH was doing things I flat out feel are wrong, SGD was getting away with and rewarded for horrible behavior like threats, physically attacking me, verbal issues ( I was asked if I was ok with you moving in, your only here because I said so, I don't like you, so leave NOW... Yep SGD said that to my face no punishment) and all DH did was excuse it and get mad at me. That was enough
As a bio parent... I'm taking BF back to court because counseling and RO and everything I am doing for DD and BS is not enough as long as he acts like this. I want to be able to tell myself and my kids I truly did everything I could to keep them safe from BF.
Soooo when is it enough??!?!?