Ewesheep, you have to take into consideration that a lot of ideas about 'husbands' and 'wives' are stereotypes from many, many years ago. In general, it is considered to be incredibly rude to ask, 'which one of you is the husband, and which one of you is the wife?' Which is like asking, which one of you is more dominant in specific unmentionable situations, which is no one's business. Of course in some situations, especially with young folks who just love to say outrageous things for a laugh, people would ask such a thing as a kind of informal joke, and expect to get a joke or get teased right back. 'And the conversation would devolve from there', into more and more outrageous teasing and jokes.
Basically, what I usually see, is a gay person will come up to me, and say, 'Hi! I'd like you to meet - Jim'(or Mary) And I say, 'Hi, Jim!(or Mary) It's great to meet you!' And I can just tell from how happy they seem together, that that's just fine. And that's all I need to think about.
If I am completely out of control or not thinking, and I somehow have to know if they are together, I'll say, 'Say, Joe, are you and Jim an item?' But in general, what I need to know is what people voluntarily tell me without being asked, and that's all I need to know.
