Genetically, first cousins are fine. It does slightly increase some risks, I think doubles at most for some very low likelihood cases. I don’t know that it’s any more irresponsible than reproducing with someone that has a family history of genetically passed diseases.

Humans were tribal until very recently, and reproducing with non-immediate relatives was normal. If it were that detrimental, we would not have survived as a species.

And no, my wife is not remotely related to me.