Getting along and being friendly with your coworker is a good thing, seeing that they are the people you spend a lot of time together at work. It will make the work more productive and less dreary.
But just like any other relationship, you need to step out boundaries. Treat the relationship between coworker as a professional thing. No matter how friendly your coworkers with you, there are things that you should never ever tell them or it could turn a working relationship ugly.
The general guideline while making conversation with your coworker is to use common sense, discretion, and obviously no insult. The things that you wouldn’t say in front of your bosses are the same thing that you won’t tell your coworker as well.
Here are a couple of things that you should never tell your coworker:
Spreading gossip is not a good idea, no matter how much it appeals to you to talk about your coworker personal life. It may seem harmless but it will affect negatively on how your coworker perceived in the office. Besides, making and spreading negative comments about other people will make you look worse than the person you are talking about and it could bite you back.
Telling a white lie to a coworker because that is the kind of thing your coworker wants to hear is not something you want to do. You may be tempted to say that your coworker is doing a great job while it actually subpar. Better stick to the truth and say something based on fact. It doesn’t mean you have to speak brutal truth, just make sure you deliver it strategically. Do not temp to tell any white lie just because you don’t want to hurt your coworker.
In the line of work, there is always something that didn’t work out as planned. Perhaps your coworker’s presentation is sucks, or maybe he/she made a mistake on doing their part of the job. In this situation, avoid unconstructive criticism. Discuss the mistakes they made specifically, how to deal with it, and are there any way to make sure it won’t happen again in the future. A positive feedback like this will work better for the company and for the relationship with your coworker.
Use common sense while making any comment to your coworker. Avoid any comment that will make you look unprofessional. For example, commenting the physical appearance of one of your coworkers may be seen as harassment and badmouthing other people in your office especially your employer will only get you into trouble. Give a negative comment about certain topics such as religion and skin color is considered unwise and unprofessional.
Never share sensitive information about your client with coworker willingly. Some people may find something about their client is worth sharing with their coworker. Sensitive and confidential information is exactly as the name stated. Keep it confidential and do not let a tiny bit of information ruin your career because you can stand not to share it with everyone.