An old contract forces Shining Armor to spend a day with his sister doing whatever she wants. She uses this opportunity to try out some techniques from the Big Book of Ballbusting.

Warning: This story is all about ballbusting and not recommended to anyone who doesn't like cbt.

Kinks: Ballbusting/CBT/testicle torture, brother-sister incest

Written for the April Incest is Wincest contest.