Responses
I've heard Japanese used to do cousin x cousin marriages as well before. Although it's at an all time low now I think they don't shun it as much as the West. Cuz over here in the US we made it illegal. I agree with OP, it's interesting to see how morality changes with each culture but as long as you take the precautions for the offspring it probably should be fine??? (I won't do it though lol)
In our culture cousins marriage is totally normal its prolly why everytime he says " but we're cousins" i be like yeah dude you really are cousins ..? Personally im against cousins marriage ( male/female couples) if they dont go through all the necessary tests to make sure they wont conceive a possibly sick child. If they are not planning to have kids or if they cant then i do not really discriminate.. most likely because i see it happen around me ( rarely cz its more of an old fashion rn)