A dominant mistress puts her male slave through a rigorous training session, focusing on his anal endurance. She teases his asshole with her fingers before introducing a large, veined dildo. The slave, though hesitant, submits to her commands, moaning in a mix of pleasure and pain as she pushes the toy deeper into his ass. The mistress, enjoying his humiliation, smirks as she forces him to take the entire length, his ass cheeks clenching and releasing around the thick shaft.