My husband (a GDI) was a little concerned about me going to mixers and fraternity parties - sort of "You have me, what do you want to go hang out at a frat [sic] for?" But I went and just had fun hanging out with my sisters and the fraternity's members. My husband knew I wasn't going to stray, and besides, it was him who I took to formals
Wooglin4Ever, I have to disagree with your statement that "non-Greeks don't understand". My husband was very understanding when I had to disappear for rush, initiation, meetings, etc - more so than the guy I dated before meeting him, who was a fraternity alum. In turn, I was understanding when we couldn't hang out because he had to go to meetings for organizations he was involved in, or when he had to study and I didn't, etc. Nobody's around their S.O. 24/7.