This is just like the “Siblings you know” game, only with couples instead of sibsets.
The first person names a couple they know, who can be either be married or simply just dating. Then the next poster mentions a couple of their own, one of whom has a name from the previous couple. For example:
[name_m]John[/name_m] and [name_f]Abigail[/name_f]
[name_f]Abigail[/name_f] and [name_m]David[/name_m]
[name_m]David[/name_m] and [name_f]Susan[/name_f]
[name_m]Jason[/name_m] and [name_f]Alice[/name_f]