I can relate.
Shortly after college, working at an ad agency, we had an IT guy who was not flamboyant but not shy about his orientation. He had me figured out, even though I was out to no one... barely myself. He would come into my little office, where my desk faced out a window so my back was to the door, unannounced. It was a large firm, so it seemed he was going out of his way to drop by, and he made me nervous as hell. He knew. And I knew he knew. And I had no idea what to do about it. He was not someone I was attracted to, and i think he may have known that too. But he just sort of let me know it was OK... that I could loosen up. And I started to. By the time I cracked open the closet door, he had moved to another firm, so i never really got to thank him for helping me along in the subtle ways he did.