I worked with an attractive lesbian 8 years older than myself. Through the years, Jen shared stories of her relationships with me. Being your somewhat typical man, I was always happy to hear of her exploits.
One of our favorite topics to discuss was her panties. She often wore thongs, and I loved the mental image of her slim, tight ass divided by a thin strip of fabric.
We were behind closed doors in her office one day discussing our dissatisfaction with our sex lives. She was going through a rough spell and I was on a forced break because of a medical issue my wife was having. In light of our situations, we were flirting more than usual, and I was growing stiffer by the minute.
When I shared this fact with Jen, she asked to see the outline of my cock through my suit pants. Both of us started breathing harder as I did so. I then asked what she had on under her dress pants. When she responded with the description of a purple, silk thong, I mentioned that I really liked the mental image. Jen then stood behind her desk and said 'what about this image?' She then unbuttoned her pants and slid them down past her wonderful butt, pulling her blouse up so I had a clear shot of her pale purple thong. Barely able to control my breathing, I said that it was better than I imagined. While admiring the view, I began rubbing myself through my pants. Since the doors did not have locks, Jen buttoned her pants after a few minutes. I could see that, despite her affinity for women, she was as turned-on as I was.
Jen next asked if she could see my dick. I unzipped my pants and pulled it out. She walked over and asked if she could touch it, telling me she had not held one since high school. She began stroking me as I reached between her legs and returned the favor. The excitement of the moment had both of us ready to orgasm in a short time. Bracing herself on my leg, an orgasm rippled through Jen. When I asked where I should cum, Jen said 'she would take care of it.' She then reached into her pants and took out a small embroidered handkerchief, which she wrapped around the tip of my dick and I shot my cum into this, soaking it. For a lesbian, she sure knew how to please a man. After I came she said it wasn't that bad. We then straightened ourselves up and went back to work.
Definitely the most exciting masturbation moment in my life.