Coworker overhears teacher talking to spouse about visa application, suggests she should have married someone from the same country: 'Why would you say that to anyone?'

Allowing an overlap of the personal and professional can be a danger zone in more ways than one.

While those who claim you should never befriend or even be too friendly with your coworkers operate at an extreme that not everybody is going to agree with, this advice does not spring up out of nowhere. Those who get unlucky with the people that they work with often run into issues when they divulge too much about their lives in the workplace.

Obviously, it is important to respect professional boundaries. Spilling all your deepest, darkest secrets on your first day is not likely to go down well with HR. At the same time, building a rapport that involves occasionally chatting about what is going on with you outside of the workplace is totally normal, and should be something that coworkers can be trusted to react appropriately to.

The unfortunate thing is that certain types of colleagues will use insight into those they work with against them, whether to compete with them professionally or simply just not be very nice. Learning who these people are and how to avoid them is often a case of trial and error, and that can come with some unpleasant experiences.