I'm so glad if gives you some clues as to other's behaviour!
I've seen those kinds of patterns in both my mum and dad's relationship (ENFJ and ISTJ) and mine (INFJ with ESTJ). I also have a friend who married an STJ (ENFP with ESTJ) and another friend dating an STJ (ISFJ with ESTJ). At least in the NF cases, I think the STJ either feels defeated or else goes on as usual despite the displays of emotion, hoping it will all sort itself out. The NF nearly always feels rejected and after years on a roller coaster of investment/hope/rejection/resentment/one way disclosure finally withdraws emotionally so that they can remain physically well. However, it remains the deepest sadness they have because they have invested everything they have into the relationship. Even if marriage and family are extremely important, it appears to me that all of the STJs eggs are not all in the one basket.
All of the aforementioned relationships are in various stages and ages in life. My parents have been together for over 40 years and their two types have in many ways been a good combination. As time has gone on though, they have increasingly led parallel existences due to unresolved conflicts, much to my mother's sorrow. They both still love each other and they are very committed to the idea of marriage. If more understanding of each other could happen, I don't think it would be too late even now for things to change. Unfortunately, I don't imagine it will.