Telling a manager about something shady at work might cost you some comfort. Keeping quiet costs you yourself.

Silence has a cost that does not appear on any balance sheet. Speaking up risks awkwardness, standing, sometimes the job itself, and those risks are real and worth weighing honestly. What you spend by saying nothing is harder to see: a slow adjustment in what you are willing to accept, which tends not to stay at work.

Write down what you saw, factually and with dates, before memory softens it. Decide who is genuinely safe to tell and what outcome you are asking for. If the place makes honesty dangerous, that is information about the place rather than about you.