Nothing quite as awkward as explaining to someone their grandparents were first cousins. Well, parents would be more awkward. #genealogy
There's a lot of judgment and ignorance around it. I don't encourage it, but the occasional one-off cousin marriage isn't that big of a deal genetically if children are even produced. (I had this conversation with a geneticist, in detail, years ago.)
I feel sorry for all the kids who are made to feel shame and embarrassment over this.
As a historian and genealogist, we're literally ALL the product of cousin marriage. It's just a matter of degree.