"In the end, the prince and the princess lived a happy life." Fairy tales always use this very general sentence to describe the marriage of the princess and the prince, without going into too much detail. Probably even the marriages in fairy tales cannot withstand careful scrutiny.
Fairy tales are like this, but what about reality?
In real life, people enter marriage with various expectations, but what follows is boredom, and they are tortured and breathless by the married life.
Concept: all kinds of marriages, all kinds of human nature.