Is this another millenial joke? Like they don't understand when you are hired by a company you work for them during office hours and not for yourself? Seems like people need a lesson in work ethics... Yes, you should be fired, and no, you don't need a reason (you can guess) from them on why unless prohibited by law. Don't do it. If you want to work on something on the side, work on it "ON THE SIDE!" not during work hours.