I dont know whether you should stay or run.  Im 75 and have stayed.  But here's what is to come: graduations, weddings, showers, babies, divorces, move backs, babysitting, grandkids going thru the same things, great-grandkids.

For me, it was about 15 years of kid hell with all 5 of them (2bios, 3 SKs) eventually moving out.  We have had 30 years of just us, it has been great!  So take the long view.  Is it worth it to eventually have those days with your DH later?  Thats the basic question.  Good luck, Lucky.

(((((HUGS))))))

Even if they are as dumb as their mother, your DH's parenting must contribute to the mix.  My SS20 is a carbon copy of BM, and I haven't laid eyes on him or spoken to him in about 7 months.  DH talks to him here and there, but he hasn't been to our house.  DH has no use for his lazy, failure to launch ways and doesn't enable it or make our home a place that SS wants to hang out in.

But if after 12 years, your DH hasn't changed his parenting, then he probably won't.

With her father and SM. Instead with her BF. Tells you everything. It's never going to get better, except the SD and her BF will be living with you 

It doesn't end. They keep playing games and them they get married and have (and withhold) their kids and the games continue forever.