"ClopySow people care because children are involved"
And?...they're suffering how?
I posted earlier about being in a child's position rather than the adults...it's not something I tell many people tbh because it gets weird reactions, reactions like the ones on this thread.
Personally I wouldn't ever choose to be in that sort of relationship - not because it's wrong, but because it would be wrong for me.
But as a child for about 3 years I lived with my mum, my dad, another woman and her children...I have literally no idea what state the relationships were in, my mum and dad were married then after that time they split up and he married the other woman. (I say other just to differentiate, because clearly my mum knew).
If I tell people about it they say things like, that must have been weird or confusing or upsetting...but do you know what? It really wasn't.
We effectively had 3 parents and extra siblings and we never even really questioned it, we were children and it was our normal...in fact it was probably the happiest and most stable part of my childhood.
So while I do think the OP has to be careful about involving her children, actually it's because of other people's reactions rather than anything to do with her own relationship/s, reactions like - there are children involved, as if extra adults in their life is inherently a bad thing.