Half a year ago, i had this kind of setting. I had a session scheduled with my favorite mistress some weeks ago as 2 days prior the session i got a message of her if i would like to have an additional mistress. I would be her very first sub an she would show her the ropes... It was a very fun afternoon, as i realized quite quickly that they were good friends, even roommates and the other girl wanted to follow her in the industry. Nevertheless, it was painful and very degrading, as she was a quick learner and my mistress showed her how 'well' i was trained and what levels of pain i would take for pleasing her.