This doesn’t exactly fit the OP, but it’s close enough, and all the names and locations have been changed.
I once worked at a company that allowed the employees to sign out their PC’s for home use. Frank just had a high end video capture card installed on his, so he signed it out to take home with him while he was on vacation so that he could learn how to use it. Well, Frank wasn’t very PC literate and was having problems getting it to work right, so he had me come over one night to work through it with him.
I was quite impressed. He had managed to connect both VCR’s he was dubbing to and from correctly and when I arrived in the room, he had a video playing of a rafting trip he had taken the year before (to be used as a test video).
I walked him through how to capture the video and audio and how to make edits and so on. The video was playing all this time and had hit the end of the tape. I rewound it to the beginning so that we could continue to do testing. When I pressed Play… there on the screen was a buck naked Frank playing with himself. Yes, he had used a partially overdubbed tape of some amature porn he had taken a few years back. His face must have turned about 5 shades of red.
In the end I told him it was no big deal and that I would keep it to myself, but he must have apologized at least 7 or 8 times that afternoon. I still bust a gut laughing when I think about it.