Major life change , such as remarriage of either former spouse. Parent-child problems . Relocation , when one person moves away. Personal hardship such as health or financial problems. Obstacles block a shift from one stage to the next.
Partners have different definitions of the relationship and different expectations.
The definition of the relationship is very different from the way partners behave. Bring out the partner's positive side. Focus on the positive aspects of the relationship. Reinterpret the partner's behavior as well-intentioned. Reduce negativity toward the partner.