I'm not going to pass any judgment on you for what you are doing... but 2 wrongs don't make a right either.
As for myself, I practice the old "Do the right thing". I don't think I could cause that kind of pain for another woman, Karma and all. not to mention what it can do to the kids if they suspect.
Your divorce will become final one way or another and you will move on, get a job, your kids will grow up, you'll sleep and be able to eat without a hole burning through your stomach eventually.
or you can just walk away without as much as you think you deserve and be done with him....get your name off the mortgage most importantly.
please believe me when I tell you that 10 years from now, none of the possessions will matter much, you earn your own money and buy your own real estate.