They're both homewreckers, just of different homes.
He's wrecking the one he made vows to.
She's building the one for her child on foundations of lies, and a whole potential shitshow of complications.
Hell, I'm never going to be mum of the year, but I set my criteria for having a child to include 'not deliberately bringing them into a messed up situation'.
(Not the same situation, but my dad proposed to my mum when they'd been going out three months. For herself, she may have said yes, but no way in hell was she doing that to my siblings.)
As a side point, yes, I judge people. I find it incredibly useful for setting my boundaries and navigating the world without harm. There are seven billion people on this planet, I don't need to be friends with all of them. Everybody exercises judgement, it's bullshit to claim you don't.
You have to judge when it's safe to cross the road, and you have to judge that a person isn't going to cause you harm. There's little difference.