The problem is that their relationship is dysfunctional in a way that feeds off both their psychological problems, so is unlikely to be curtailed without outside intervention (which they are highly unlikely to seek).
Rachel hasn’t developed past the pre-teen age, emotionally. She is stuck at the age she was when her Mum left. Despite all her talk of therapy, it doesn’t appear to have fundamentally changed her. She is still entrenched in this trauma when it comes to all her relationships, and the role play provides a sort of relief. It also shows in the way that she seems unable to provide proper parenting boundaries with her own children; she isn’t capable even if she wanted to. She is only comfortable playing the role of needy child, adored by the parent.
Sadly they are an almost perfect , if highly dysfunctional, ‘match’. Josh, for reasons unknown to us, thrives on being needed and will ignore almost anything else in order to fulfil that role.
They are a physiologists wet dream. It’s unbelievably harmful for their children to grow up thinking that is a normal relationship, and even worse when you add it to the fact that their difficult early childhoods-and the over sharing of intimate (but very normal) childhood problems — are thrust into the public eye at every turn.
This is a decent read if anyone is interested in the parent/child aspect.
https://www.verywellmind.com/parenting-your-spouse-is-not-okay-2302899