I definately agree that the spousal relationship is far more important than the sisterhood/brotherhood one, although this in no way justifies telling the secrets!!! IMHO, you should deal with an inquisitive non-Greek's questions about secrets constructively ("Hun, I love you, but I took an important oath that is very serious to me. It in no way affects my commitment to you--I took an oath when we got married, and my commitment to keep my GLO's secrets shows that I am able to keep oaths, rather than displaying that I don't trust you") rather than lashing out (WHAT?!?! I'll DIVORCE you if you ask that!!!"). No offense Tom, I love you, but maybe that's why you ARE divorced....
But yeah I think that there are a lot of marital/familial secrecy breeches. For example, in my chapter one sister's mother was a member of an NPC sorority we don't have at my school, and she told me that when she was little her mom told her and her dad some of the secrets that she "vaguely" remembered. I think people end up viewing things like grips, etc, as somewhat quaint, rather than highly meaningful. It's a shame but that's the way it is.