If you only care about the fetishes, reading the original story is not required.

Rarity, her mind split into the twin aspects of herself and the sultry, submissive Valiente, has struggled to re-integrate with the population of Ponyville after a traumatic and life-changing expedition to gather gems in the Badlands. When Valiente discovers that Applejack has been using Rarity as an unwitting backup plan in case of self-bondage gone wrong, she doesn't mind. She just wants in on the fun.

Self-edited. Pre-read by Penalt and Canary in the Coal Mine, with additional contributions by Damaged.