This happened to me the other night, and was amazing!
Back story first though. 'lucy' had been a junior in the office for a couple of months, she was straight out of university, so a couple of years younger than me. Lucy had long dark hair with pale skin, very petite, small b cup breasts and an amazing smile.
We didn't work together often, but got on well and talked quite a bit. We flirted a little and it was obvious there was an attraction, but as we worked in a office were you can't keep anything quiet, nothing happened.