两个女主人带两个奴隶参加打屁股耐力测试，以选择他们的私人奴隶

Two Mistresses bring two slaves from the slave market. Mistresses name the slaves #1 and #2, and test how durable the two slaves are to choose a slave. First, Mistresses make slave #1 get on all fours, and one Mistress starts spanking the slave's ass with a spanking paddle. The slave has to count each time the spanking paddle hits his ass. The slave makes a mistake because of the hurt in his ass, and starts over from #1, and is spanked endlessly. When the slave's ass becomes red and swollen, the second Mistress starts spanking him with the spanking paddle. At the end, the two Mistresses spank the slave's ass at the same time and laugh. Mistresses get even more excited when the slave screams, and continue spanking the slave's ass hard while getting their pussies wet. When the Mistresses finish spanking slave #1, they do the same to slave #2 with a grin on their face. Once Mistresses have completed the endurance test on both slaves, they select one of them to be their personal slave.