

Keyrings make great nipple clamps. Assuming you have pliers to install and remove them.
This was a simple standalone experiment. No video or complex bondage. Just "What happens when you keyring a masochists nipple? "
I found out : This was an instant non-stop orgasm. This was so intense that the pain / pleasure thrashing caused some limb injuries. This is very intense, and definitely going to find its way into future work we do, with the model restrained heavily - for her own safety.