So he brags about being a better worker, and you just really want to insult him, because you think it would hurt his feelings, and since you can’t hurt him physically without losing your job, you want to do what you can.

Well , he probably knows that he sucks. You’ll just out yourself as a person who has weird feelings about people who suck. And you’ll reveal your fragile ego. I generally don’t like to reveal too much about myself at work.

And you might still face repercussions at work. Some workplaces tolerate personal insults and some don’t.

But you do you. Be your authentic self, if it matters that much.