kids are always the collateral damage in divorce

Same story, different children. Nothing you can do about it...kids will be hers to take care of and you will support them. That's how it is set up. You can fight all you want, but it won't matter. Ex will fill their heads with fecal, you know it's coming, deal with it head on when it's your time with them. Don't badmouth the ex, that won't do any good. Eventually you will have a chance at success with the kids once they grow up and they'll remember that you weren't an a**hole towards her and that she was the reason their lives were upended.

There is no easy way to say these things, been through many of these with my parents as the kid transferred from this parent to that situation. It's always the other guy's fault. Always. Don't play that game. You can say that she had an affair, which is true, but to keep harping on it does no good. Go on with life and seek out Miss Right II.