>>212805610They are building up to this, why do you think Gunn was so clear about his parents having such "American" accents. I mean Superman talks normally in the film, but his "mom and pop" practically need subtitles and you get a strong impression they own a moonshine stil in the woods or a goldmine.
For Clark to have been raised in a set up like that, marrying his cousin is probably the most natural thing to him and going out with Lois, a liberal repoerter with "book-lernin' " and no genetic relation to him is actually the weird thing.