Julia-Eva decides to teach her slave for beeing a good human stool, for this he has to train his ability to support her weight.
This time she treatens his chest and ribcage under her heavy ass.
His chest is her stool and she sit on it in various positions, letting him to learning to support her.
After some minutes she thinks she must get heavier, she grabs two 5 kg dumbels and sits back on him.
Now, with more weight, the pressure to his chest is higher and the breathing gets more difficult....
More pain > more training-effect!