Unless you're using your parents address to avoid municipal or state taxes ("a couple miles" puts you in a state with no income tax), I can't see any government agency getting bent out of shape about this. What you are doing is essentially the same as having a post office box--you have a mailing address and a physical address. In your case, the only difference is that other people live at your mailing address (who are related to you) and you are (presumably) not paying them a fee to collect your mail.
I am speculating, but I bet you use your parents' address because it's more secure for mail, somehow. Pretty much anyone would understand that as a reason.
Last edited by fwoomp; May 18, 2015 at 11:26 pm
Reason: "Orfice" is not a word, and I didn't want the one it suggests!