SeasonedPoly, I don't understand where you're coming from. It sounds like you just don't like parallel poly and are being weirdly judgmental about it. I don't understand why you think parallel poly would be impossible or unhealthy with kids involved.
It could function just like many ex-wife / stepmom situations where good boundaries are the key to maintaining a perfectly cordial, healthy two-family set-up. With poly, you can have the same set-up except with two ongoing relationships instead an ex & a new wife.
The model for poly doesn't have to be "everybody living together as one family." We can create other models.
I also don't understand the objection to the term/concept of "auntie" for a parent's other partner. I don't think an "aunt" is defined by being in a non-sexual relationship to a parent; I mean, it seems weird to define it that way.
I find your response very strange. Firstly, I'm not against parallel poly with kids. I'm against a structure which is parallel because the people involved do not like each other enough to share more space.
There's a big difference between a friend of mine who lives being a father but is very reclusive and loves his wife to go off to her other partner's house and someone who can't bear his metamour so intentionally spends time away from him. He has a long distance partner who he probably sees every couple of years but speaks to on Skype a lot. Or they facetime but don't talk much. He's a hermit and becoming more so as he ages.
They don't have young kids but if they did, their situation doesn't give me the same concerns. If he really got on with a metamour, he'd spend 1v1 time with them like he does a select few friends. It wouldn't be KTP. And most importantly, they can peacefully share space when it is necessary to be a good partner to their hinge.
I said earlier that I think it is different when you're dealing with an ex (who isn't your co-habiting partner) and your current partner(s) than when it is 2 current partners with whom you share residential responsibilities. That's why people who are forced to live with their ex due to finances or other practicalities rarely find the space to develop healthy new relationships. A friend once asked me if I think she has a better chance of doing this successfully because she is poly and I said no. Living with an ex is living with an ex. Works for very few. I was right. They now rotate between the family house and a small apartment to share custody.
I don't think they have to live together at all. What I think is that their preexisting conflict and negative feelings mean that this set up +/- the OP maybe adding more kids to the mix is incredibly risky for the emotional wellbeing of said kids. If that wasn't the case and things like her access to the home her partner lives in wasn't influenced so much by their history, then the fact they have limited contact wouldn't matter as much IMO.
For example, Dagferi lives between 2 houses which run quite independently of each other. My understanding is that it is both her husband's preference to not socialise with each other very much. I've never commented on that situation because I in no way get the impression that it is because the 2 dislike each other and have had a tumultuous history. I might be wrong and if so, my opinion could change on that situation.
I definitely think aunt refers to someone that your parents are not sexually intimate with. I mean think of it, your aunts are your parent's and grandparent's siblings and maybe some of their cousins and friends you might refer to as Aunt. How many of your aunts have you seen in your parents bed in the same way you might see them in bed with each other?