So Eltern is normally a feminine noun. Here it's in the dative so it should take take masculine of "der". Which would lead to "was ist mit meiner Eltern?" instead of "meinen". That was my initial thought.
However, am I write in thinking the "n" in "meinen" is coming from the "dienen" article? On Duo's chart thing it says plural nouns take the form "dienen". Am I right in thinking this?
I think Eltern normally takes "die" because it's plural, not because it's feminine. This would explain why it's "meinen" rather than "meiner", as the dative plural declension of "mein" is "meinen".
("Dein", like "mein", follows the declension pattern of "ein" too, which is why it would also be "deinen". See: http://en.wikipedia.org/wiki/German_declension#Indefinite_articles.5B2.5D)
Can anyone attest to how natural this sentence is in German? I was a bit surprised that this is word for word translated from what I would say in English, 'What is with my parents?'.