Link: https://meninchains.com/

"Welcome to the leading porn-free male bondage website on the internet. We feature male bondage videos that contain no porn.

We feature fictional screenplays, documentaries, and a variety of videos that have male bondage as the central theme.

The site also contains writings by Mark Bind."

And the site has a special section about selfbondage:

https://meninchains.com/self-bondage