Let this story serve as a friendly reminder that just because someone placed their mug in the office kitchen does not mean it is up for grabs. This can be a common misconception, so if a coworker makes the mistake of using your personal mug once or twice, you should give that person the benefit of the doubt. They probably just did not know otherwise. That being said, if it happens on more than a couple of occasions after you requested that this person not use your mug without permission, then we’ve got. problem.
When this kind of repeated scenario occurs, you can assume that it’s beyond an accident. It’s a sign of disrespect and a refusal to accept your simple wishes. Sure, you may think I’m being overdramatic, but if you let someone disregard your boundaries at work, you could be in for more trouble. Today it may be a coffee mug, but tomorrow it could be more serious. That’s why establishing and reinforcing those boundaries are crucial. If your coworker crosses that boundary, then you are well within your right to get even!