{{Couple ancestors}} displays a list of common ancestors of husband and wife reverse-ordered by year-of-birth-as-string.
Type or paste {{Couple ancestors}} at any point on an individual's page where you would like to see a table of ancestors common to that individual and his or her first five spouses.
At the bottom of the page of the nearest common ancestor, there is a list of descendants including the generation numbers of husband and wife'. You can use this to work out the rough relationship between people. For instance, if husband is generation 13 and wife generation 15, then they are 11th (13-2) cousins twice (15-13) removed. (This will be automated in due course.)
There is an ahnentafel at the bottom of the pages of husband and wife. The number specifies the exact relationship between husband or wife and the nearest common ancestor. For instance, 16 means the paternal grandfather's paternal grandfather, and 62 the maternal grandmother's maternal grandmother's father.