The office where I work is in an older restored building, but it faces across the street to a new glass skyscraper, the kind with perfect "mirror" panels that provide such an accurate reflection that I could comb my hair or shave in it.
Immediately below my office there is a law office, and I've often chatted with the attractive paralegal who works literally underneath me. She's in her early forties, divorced with two kids, and has what they would call a "smokin' " body. We've gone out for drinks with a group a couple of times, but have never really flirted seriously. "Deb" dresses very young for her age, and is not afraid to show off her legs and cleavage. Her nickname around the building is "Erin Brockovich", which ought to give you the idea.
One Friday late last summer I was working late, musing on something or other while staring out my window when I noticed that "Deb" had turned her chair to her own window and was also gazing vacantly into space. It was a mercilessly hot day and our building's AC was straining to capacity.
Although I noticed her in her reflection, she seemed unaware of my gaze. I was beginning to stare as she rolled her desk chair up to the low, full window and lifted up the sash (she has the only window in the building that actually opens!). I could not take my eyes off her as she shook off her heels and put her feet on the windowsill. I was mesmerized as she slid a hand up the inside of her bare thigh, straining to see whatever she was about to expose.
She soon gratified my desire, as it became apparent that she was not wearing panties, her hand sliding her skirt up above her fully shaved bush, and moving gently up and down her mound. I was instantly hard as a rock.