Yes. Not only was he a coworker, he was my boss. I worked in a convenience store for a couple of months while I was looking for a job after a layoff. We worked relatively closely and became friendly. One night early on in my stint there, he was training me on how to close the store at night. Now, he normally only worked during the day as he was the manager of the store and the assistant manager, or one of the other associates would close. However, the person who was supposed to close was sick and the assistant was out of town, so he was there instead. He was strictly professional while we were working, but midnight came and we closed the store, and then went into his office in the back to see if I had any questions or concerns. Then we just started talking and joking around in his cramped little office. A few times while we were talking, he would brush his hand against my leg or just slap my knee while we were talking. I didn't think anything of it, but after awhile I noticed that his touch was lingering, and was also moving distinctly upward toward my waist. I didn't say anything, but I looked at him and he looked at me with look that was halfway between a smirk and being worried that I'd get up, walk out and sue for sexual harassment. Instead, I just leaned back in the chair and let him continue touching me. He smiled and moved his hands up my pants and started feeling around my cock which was starting to swell. He unzipped my pants and took hold of me and began to stroke me. I leaned back farther in my chair and he unbuttoned my pants and pulled them off. When I didn't protest, he took me by the hand and pulled me up to my feet. He then put his hands up my shirt and started feeling my stomach and my chest, and then I helped him remove my shirt. He leaned in, and kissed my neck, then looked at me and it was as if he asked me if I wanted to continue without saying a word. I didn't say anything, it was almost like I didn't have to.He opened took a condom out of a drawer in his desk, then he turned me around and had me bend over his desk, where he entered me from behind. He slid in slowly and began thrusting into me. We fucked for about 15 minutes or so before he finished. We got dressed and left the store together.
The next day at work, we didn't say anything about it, but we'd pass a quick glance and a smirk. It became an inside joke between us, and we continued to fuck for the rest of my employment there. In fact, we still fuck to this day. He is one of my 2 regular guys, and they know about each other, and we have even had threeways from time to time, though, it is more like a gangbang because they are both tops, so they basically take turns on me when we go that route.
So yeah, it worked out for me, and just telling that store has me all worked up