In the Harry Potter universe, we see huge differences between wizarding culture and Muggle culture. The differences are so huge that one culture is almost alien to the other.
We also see marriages between wizards/witches and Muggles, as well as lots of half-bloods.
I am curious to know how social syncretism works after such marriages, on average. Do their kids follow wizarding culture or Muggle culture or an amalgamation of both? Do we have a close picture of such families?
I don't think such marriages would work well, on average.
We have the quote from Seamus Finnigan about his parents
“Me dad’s a Muggle; Mum’s a witch. Bit of a nasty shock for him when he found out.”
This is probably an understatement. Imagine you marry someone, and after the wedding they say "I have to tell you something." Would you ever again trust them to tell you something that is important for you and your relation? I don't think so. Yes, it is a consequence of wizarding law, but that wouldn't make me feel better.
The situation is different when a child turns out to be magical. The child didn't choose to hide anything, and it is still the child of the parents, although I think some parents would still have a bad reaction to such a revelation. Imagine one of Dudley's children is magical. Since magic is hereditary and Lily was magical, it is possible. Would the love for their son and his children or the aversion against freakishness win?
On a practical level, not telling the family and friends of the spouse means that you either can't meet them or have to be very careful. This in turn will add stress to the marriage. Most magicals seem either unable or unwilling to fit into muggle culture. Even Arthur Weasley, supposedly interested in Muggles, is not motivated enough to learn to pronounce electricity even after Hermione corrects him. Deaths of muggles are not considered important. Even in the epilogue Ron sees nothing wrong with confounding the examiner for his driving license. He even admits it to the Head Auror (Harry), who also doesn't think it is wrong.
“As a matter of fact, I did Confund him,”
This shows a general disrespect against muggles, and that means it is not likely that a magical would want to get to know a muggle enough to even consider marriage.
