I was working late at the office one time, the cleaners had been in and gone. I just finished up, powered down, and ready to get home.. As I was just leaving the main office I heard a noise in a side office.. stupidly, I guess, I went to look.. as I looked in there was Mike sat on his seat.. trousers and boxers down past his knees, stroking his cock. Our eyes met, both in shock and disbelief. He tried to cover over his erection, saying 'sorry' the same spit second as I did.. I just stood there saying I'd had to finish off a report.. all the time staring at his hand covered hard cock. He looked at me saying 'please don't say anything'.. I sighed and said 'well you better take your hand away then' and walked closer.. I stood infront of him in his chair, he pulled his hand away, I just stared at his exposed hard cock. Again he said 'please don't say anything'. I took another half a step closer saying 'well let's see' as I reached to take hold of his cock in my hand. He felt so hard in my palm, all warm and throbbing as I stoked up and then down. As I moved up his precum started to ooze out his head eye. Slowly but surely I started wanking off his needing cock. My nipples and clitty were both tingling as I played with his cock. Watching my hand stroking him off, seeing more n more of his precum coating his cock head and shaft as my hand moved faster and faster up and down on him.. he made a few noises and then moaned 'I'm gonna cum'. I continued then stopped still as I watched his cock shoot out his cum ropes all over his nice white shirt. 3 or 4 good blasts then the small trickle as I stroked him again. I stopped, wiped my cum covered hand on his trousers and thanked him for being there and told him I'd never seen him that evening...