Yep.
My Mum had a terrible attitude towards his second wife - I sort of don’t blame her, she was the OW, and was left with 3 under 5 to look after whilst he fucked off into the sunset, she’s human and was bitter. But the damage she caused to me and my brothers runs deep and I’ll never forgive her for it.
Had no issues moving step Dad in after only knowing him for 3 months, but we had to sit in my Dads car in car parks on contact days because God forbid That Woman even breathe near us. (He did take us out a lot but also was running up huge legal bills taking her to court constantly for breaking the court order).
She was like a banshee at every pick up and drop off and would ring him at least twice a week to kick off over nothing.
ExH also fucked off with OW (not the wife), leaving me with 2 under 3. I busted my ass to not be my mother in that situation. I got myself into therapy, vented and cried to my friends and slapped a smile on whenever he picked the kids up.
Fortunately OW had zero interest in “those children” and said “in my mind they don’t exist” — charming. It only lasted a year, I dread to think what would have happened if she’d stuck around.
So when he met his wife, I was, frankly, relieved that she was interested in DCs, took it slowly with them, asked if I wanted to meet for coffee first (we did, it was awkward but she felt like it was the right thing, and I appreciated that she wanted to meet the mother of her partners children so I made the effort), has always been pleasant when she’s done pick up/drop off or when I’ve done it and she was home from work before ExH, is basically another adult that cares deeply about my children and I fail to see how that’s a bad thing.