Young people need to be prepared for adulthood so that they are ready to use their genitals properly and safely. Madame shows them the technique of intercourse, teaches them how to suck and swallow and demonstrates by personal example how to get an orgasm. The young men really liked the lesson - they absorb all the knowledge with genuine interest. The adult woman seems quite happy with the result. I have no doubt they will repeat the lesson on their own!
If I found out my sister was a slut, I would have pulled her in the asshole, too. For these guys, getting their asses handed to them is commonplace. Although for the look, they break for a few minutes, but when a couple of drops of lube appear - they quickly sit down anally on the phallus. So this little sister is nice to feel like a courtesan, to show off all her skills in front of her brother, to let him cum in her ass. Every bitch dreams of being the best at it.