Well that makes sense

So I was chatting with a German friend of mine, planning my time for my impending trip to Munich. I was mentioning my friend was arriving on the Monday after.

"Your boyfriend?" he asked me (in German).

"I'm single," I responded back. (I'm translating.) "You know that."

He went on to explain something about German that was never quite clear to me until that moment.

German, like many other languages, has gender. In heterosexual relationships, if you say you have a "Freundin", it's automatically assumed by female friend that means girlfriend. Quite the opposite, since English has no gender, you can say a friend referring to a girl and no closer relationship is assumed. Also in German, if you have a wife, you would refer to her a "meine Frau", or literally "my woman". While that would be appauling to say in English, there's no such connotation of ownership in German, just that she's not someone else's woman.

So I wondered, what about if you're in a same sex relationship?

Well, combining the two ideas, you would refer to your boyfriend as "mein Freund". He's not someone else's boyfriend, he's just yours. So how would you refer to a casual acquaintance? I asked.

"Ein Freund von mir", or literally "a friend of mine". As in, he's a friend of yours, but he's not only your friend. It's the same idea that the Spanish say "Dios mio". It's "my God", but the "my" goes after, because he doesn't just belong to you, like a book or something else would.

As I pondered this, I realized why everyone though my travelling companion last year in Germany was my boyfriend, despite several attempts at clarification. People kept asking me, "Is he your friend?" to which of course I responded back "Why yes he is."

Now I know the correct answer to their query. :-)