Over time I've stumbled across a few examples of where distance cousins married and often wondered if they knew that they were they were distantly related.
Here are a couple that spring to mind.
Firstly, the marriage of John H P Oliver, the son of Harry Oliver who founded the Olivers garages in Long Hanborough who married Kathleen Franklin in 1961. John and Kathleens Grandparents were brother and sister.
Then we have the marriage of Charles Oliver and Charlotte Matilda Langford in 1873. In this instance Charles' father and Charlotte Grandfather are brother and sister. On that information alone and not seeing the tree you might think that there would be quite an age different, however no, its really that Charles was the 'last' son of John and Charlottes father was the first son of her Grandmother Charlotte - so generations became out of sync a little.
Finally, in this third example Maria Oliver and Gabriel Griffins great-grandparents were brother and sister.
I'm sure there is a correct 'second or third, once removed, this, that or another' to describe the relationships of the partners however I must confess I'm not that up on the terminology and how the system works - sorry.