Yes. BM tried for a long time to turn the boys against DH. It didn't work and has pushed OSS to keep BM at arm's length. YSS seems pretty indifferent towards both his parents, but he's also 14 so that might explain it.

I will say, though, that my DH's situation seems like a rarity. DH was honest when the kids asked questions, and BM does enough stupid stuff in her life that the boys see where she causes her own misery. Her narrative against DH kinda falls apart when he shows up and does his job as a dad.

Some kids can't wait to escape their overbearing parents. It doesn't necessarily mean it will drive them to the other parent but it may hurt her relationship with BM in the long run. BM may get cut off once the kid realizes she is toxic but the damage is done with BD from years of alienation and loss of closeness.

I have heard it can but not in my experience. 

No.....

Yes. IME, it wasn't so much that they suddenly saw through the (mainly subtle) alienation, but that they started to see BM's personality issues in general more clearly, and that broke her overall mental control over them. 

Yes, in fact, even adults who've been completely alienated for years can end up estranged from the alienating parent when they realize what happened. And there are kids for whom alienation doesn't work at all, because they see through it right from the beginning. BUT, be mindful, that not all parental alienation presents itself as "hating the other parent". Good alienators convince the kid that they themselves hate the parent, and that they came to that conclusion all on their own, without any input from the alienating parent.  So it takes a lot of digging for them to eventually see how the alienating parent manipulated them into thinking that.

Though not the usual CP driven PAS my SS's SpermClan tried for a decade or more to demonize his mother, canonize his Spermidiot and to poison him against our half of the blended family equation.

Ultimately he proved to be smarter than the shallow and polluted half of his gene pool and recognizes them fir what they are.

He is extremely close to his mom and I and has little to do with his SpermClan.

In our case it has backfired with NPD BM alienating both SDs against DH and me from a very early age.  The result has been that if she had not done so, both SDs would have had a SM who was in their corner and very supportive, as I have been for both my bio daughters.  As it is, she has soured any chance of a relationship and even now, I can't bear to be in my SDs' company for more than a few hours.  I think now that they're in their 20s, they may have started to realise that I am, in fact, human and not an alien monster, but it is all far too late.  I loathe them and probably always will. 

Nope

Before I got divorced narcisstic grandma of step kids used the her grandkids and own kids as ‘agents’ for her own agenda. - but they are so enmeshed they will never be able to see it. It this case it was grandma and not bio mum that estranged the children from their dad. 

I guess we just have to hope that one day they can take a step back and see people for who they are. 

My youngest is from my second marriage and ex has tried to alienate him from me and his half-sibs. There was lots of drama for years, lawyers, court, but not my youngest gets snarky with his dad and sarcastically says "Child Abuse! she's abusing me!" at the most ridiculous things.  Since the youngest has been a snarky teen the alienation drama has stopped.  

Usually parental alienation goes hand in hand with emeshment. So it doesn't usually backfire in the form of the alienated child seeing through the bs and forming a closer bond with the alienated parent. What can happen is they fail to adult properly and end up with a permanent child mentality. If the original goal was to raise a functioning member of society then the parental alienation has backfired on that. But sucks to be the alienated parent - not much hope on that front.