[AppyPappy]

My in-laws were first cousins. I had an ancestor who married a first cousin in the 1700’s.

[goodnesswins]

My great great grandparents were first cousins...had four apparently normal children...but maybe that is why my sister is schizo?

[Flaming Conservative]

I read a lot of novels from the 1800’s. Seems like marrying your first cousin was a thing. Of course, they’re novels, and I doubt if science was a part of their research.

[NorthMountain]

My in-laws were first cousins. I had an ancestor who married a first cousin in the 1700’s.

Odds are you'll get away with it if your temporally extended family doesn't try it too often. Otherwise ... you end up like European "Royalty" ...