Bondage trousers
From wipipedia.org
Bondage trousers (US: Bondage pants) are trousers covered in various straps, chains, buckles and other paraphernalia to give the illusion of a bondage harness. They are common in the punk or Goth cultures.
Originally, they were made of leather. They are now more commonly made of cloth, often with a taertan pattern.
