When it's time for slaves' anal expansion, Mistress makes a hole in the slaves' underwear and says, "Oh, your anus is completely visible, ha ha ha." Mistress plays with slaves' anus by inserting and removing her fingers at the same time. Mistress makes slaves get on all fours with their butts facing each other, connects two dildos with duct tape, and inserts them into the slaves' anus. A line is drawn on the floor in front of slaves with duct tape, and the Mistress makes the slaves fight by pushing their butts against each other. If they go beyond the duct tape, they lose. Slaves try to win the game by pushing their butts against each other, but the dildos penetrate the depths of their anus and cause them pain. Mistress whips the slaves and says, "Good luck! It's an automatic anal expansion game! ha ha ha." As punishment, Mistress fucks the anus of slave who lost the game with a strap-on to train it to be stronger.