Today at work, I stumbled upon a collection of private photos taken by my two bosses (they are a married couple, and own the business). The photos in question are of a lewd nature of one of them. They are stored on a server where anybody in the company can access these files.

It is part of my role to organise and keep the file storage clean ("clean"), so it is not out of place for me to look around in random folders.

How should I move forward in this situation? Should I delete the photos and say nothing, should I tell my bosses about my discovery, or should I do nothing and try to move on like nothing happened?