Based on the individual terms in the filename, it likely refers to one of the following:
The term "GymDudes" combined with "Horseplay" often appears in titles for prank videos or amateur fitness-related comedy clips.
This specific filename structure (combining .wmv and .mp4 extensions) is often characteristic of files shared on peer-to-peer (P2P) networks, older internet forums, or "shock" video sites rather than official media releases. Contextual Possibilities