Do Not Spread Rumors About Your Coworker

In American culture, at least, I could say that we do look down on gossiping. It's not a good thing. We don't want to do it to build. We want to build good relationships at work. Do your best to stay away from spreading rumors. Even if the person is your friend and you're trying to tell your friend something about another coworker, you shouldn't do it because eventually they can't trust you.