Simon Smith was found dead in a cupboard wearing a latex mask after a solo sex game went wrong.
An inquest has heard that Smith, a former funeral director from Wales, had been playing a solo sex game called "breath play" and died accidentally.
The game, which is reportedly also known as erotic asphyxiation, involves restricting oxygen flow to the brain.
Some people feel sexually aroused and experience pleasure associated with lightheadedness from the restricted oxygen.
It was found that Smith, 38, lost control and eventually died.