Yes, Rhinestone, I agree w/ Smileless and Namsmanny. It may be convenient for ES to live with (live off of?) his dad, but, IMO, he's also making him "pay" for the past, figuratively as well as literally. And your X is probably hoping this somehow makes up for the abuse (which, of course, it doesn't).
Agnurse, I totally appreciate what you're saying. I think it's terribly irresponsible, though, if they expose their kids to the abuser. But I guess if they've suppressed or minized the abuse in their minds, they don't see the abusive parent as such a threat to their child.
Smileless, IDK, but I imagine if an AC is lying about abuse, they don't feel as if it means their childhood wasn't safe, etc. - b/c they're making it all up. Also, no doubt, some people do remember and acknowledge any abuse. IMO, agnurse's comments only apply to some abuse survivors, and may apply to Rhinestone's ES, even though I think your analysis of that situation is more likely.