It's hard to make that one work in poly dynamics. Because there are all sorts of LONG TERM relationships that aren't spouses.
My husband and I have been together for 15 years. But my boyfriend and I have been together for almost 21.
When shit hit the fan-as it sometimes will-the one who had the longevity-was my boyfriend, not my husband. That he also had bonds with every one of the children-and had a bond with the oldest for 5 years longer, played into things as well.
"Love As Thou Wilt"