Based on the format, here is what the components typically refer to in that context:
Many creators used a "reality-style" format. The "ended bad" part of the title often referred to the creator being "caught" by a family member or roommate (playing into the "My Brother's Girlfriend" narrative), adding a layer of staged drama that helped the video go viral.
It seems you’re referring to a specific video file title: “mybrosgf e16 monika nylon experiments ended bad.wmv”. This appears to be a user-named clip, possibly from a private or niche collection (e.g., ASMR, fetish material, or a vlog-style experiment involving nylon clothing).