Perhaps she was only dusting because the other end of her duster was afixed to her genitals, and she decided that she needed a more satisfying romance than the one sided-subtle eyeing up that she was managing from you. Perhaps she glimpsed you from across a hallway, your eyes meeting in a moment that said "I want you". Perhaps your eyes told each other that you wanted to be with them. Perhaps the heart just wouldn't say no.
Then again, "No Steve. Just No. Go and have a wank".