There have been cases where a "marriage" was disputed after a separation of the husband-wife when no actual divorce occurred, and then long after the separation (years, months, days, or hours after, who knows) one of the two gets married again while still legally married to the first spouse.
The dispute here being over whether or not the two were still considered as married and/or whether or not the second "marriage" has any beneficiary rights as a "spouse" to and of the benefits in the plan. Of course this comes up when a lot of moola is at stake after the death of person who was double-married, and both "spouses" make a claim for the benefits.
"Double-married?" . . . hmmm maybe that term will also be allowed to be considered as "married" now that the one man and one woman terminology has gone away?