I don't approve of the way dps ex treated him but we do get on well.
She has never bad mouthed me and has been quite accepting apart from a wobblle when I first got with him. She didn't kick off but she felt sad( she was with her lover so couldn't grumble really.)
I've been in her house and she comes in mine. I don't think the boundaries are too bad but have risen above it for the kids.
There were boundary issues at first but I think things are much better now.