A few years ago I was visiting the groundsman shed at work and chatting to him about work and things. He had just been digging around all morning and was pretty dirty and we were chatting about that. I made a joke that he's a "dirty guy" and we laughed, then he said "I can fix that".
He proceeded to strip out if his clothes and into his underwear. Was not expecting it, he's quite the looker, tall, slim and hairy. He asked we " what do you think", I said that it was a great look on him. He said "well I'm in my undies, now you have to". So I proceeded to strip to my underwear too.
We both stood there in our underwear looking at each other and laughing. He said "looks like my undies are dirty too", and then took them off. I took mine off too so we matched. His willy was a nice 4" cut and he had the biggest bush of pubic hair I'd ever seen. He made comment " like my bush? Touch it".
I ran my fingers through his pubes and grabbed his willy, he became hard very fast. We then walked over to the shower in the shed and washed each other with our dicks both standing tall.
The most intimate experience I've had with a coworker.