Most Helpful Guy
First is knowing what sorta relationship you are with him? secondly do you want to be in a specific relationship with him? if you really like him then just tell him unless he was a sorta player that just sleeps around.
Sleeping with a worker that you work with isn't necessary a mistake just awkward if it turns out wrong.
Most Helpful Girl
I think having sex with a guy you work with is a huge mistake. But there is nothing you can do about it now. I think when women have sex with a guy who they are not in a relationship with they get insecure when they usually are not and think something is wrong with them.