This recent question felt borderline to me, and, to date, has received 2 close votes.
The question is really about how the mother and father relate to each other, and the answers it is garnering are more relationship advice than parenting advice. Granted, the context of the question is related to parenting, but the question itself is more about communication in a relationship, and the answers given would be just as valid for any number of questions not at all related to parenting.
In a previous discussion, it seems that questions from the perspective of a child asking about interacting with their parents are on topic. The main rational is that these types of questions are useful to parents, and therefore should be allowed.
Should this be extended to include questions like this one, that are useful to parents, yet not necessarily directly related to parenting?