Wow... sounds like the beginning of a story. Too bad he wasn't the inexplicably sexy and shirtless decorator.

I knew a girl whom I was *positive* was a sub, although I'm not sure she was aware of it herself. She was in poetry class with me, dressed very fashionably, and always wore these shiny, black boots, with pointy toes, stiletto heels, and big buckles. The boots contrasted with almost everything else about her -- she was very sweet and timid and had a reputation for being a rich "daddy's girl" (a common stereotype at the college I went to, considering how high a tuition most of the parents were paying). Her hair was usually pulled back tight, she wore tailored jackets and shirts (she had work right after class, so she dressed in her work clothes), and her posture was excellent.

I had my suspicions, but they were pretty much confirmed when she brought in a (very good) poem that she'd written about her boyfriend. It was very romantic and sexy, and there were just a few lines that indicated that he held more power over her -- at least inside her head -- than is completely "normal." She said -- when a couple of people raised the issue in the workshop -- that she had just meant to write a sweet, romantic poem, without anything dark or weird going on... but it was pretty clear to me that her idea of romantic was, um, very similar to my own.

So yeah, I think it probably takes one to know one. I agree with the poster above that you probably cast your eyes down -- to someone in the know, that would be a dead giveaway.