Girl, you and me both. It's really none of his business anyway, but I've had quite a few dudes ask this question. Half the time, I get smart and say, "Because I'm smart." But I mean, really, they act like there must be something wrong if you're single...like if you were legit you'd have a man. That is sooo not the case. Half the time, the sane & sophisticated ladies are single b/c they're not settling for all this foolishness goin on.
A couple of weeks ago, this guy that I'm talking to asked me that question, and I just asked it back instead of answering it. Once he heard how stupid and rude it sounds, he apologized and found a more polite way of asking if I was single by choice which was what he wanted to know. I told him that he shouldn't ask anyone else that b/c it's rude and annoying...if there's something specific he's after, he should simple ask. I think he appreciated me schooling him on that.