Mistress Iside - treatment

I have been training this slave because I see in him the necessary capability to become a good masochist slave. Even if I have already severely tested his back with a very hard whipping, I don't fully know his potential yet and now it's time to test his ass with my terrible canes. He's already positioned on the steel equine; his training has just started and I am anxious to discover the endurance of this young butt. I want to see whether he will be up to my expectations ..... let's see ....