It can be pretty shocking to think a couple that's been together for years and years might divorce at some point, but it does happen. Once a couple is more established, we think they've weathered any storms that have come their way, when in reality, they may simply have learned to live with each other. The dealbreakers at this phase of life usually are definitive - infidelity, abuse, money problems, disagreements about children, addiction - but some may just be niggling issues that have worn the couple out over the years, such as a lack of passion, sexual miscommunication and changing priorities. People change, and so do their interests. A partner's lack of interest, accommodation or flexibility about the other's new passions, such as volunteerism, politics or anything else, can cause major problems. It boils down to partners valuing one another and attempting to understand each other as they navigate life together.