Mistress Zora and I, Lady Nora, have been for a walk, during which we discussed the slave's shortcomings. Holding his breath is not his strong point, so we want to develop this as his new skill. I sit on his belly and press both hands firmly over his nose and mouth. It is now impossible for him to breathe. But this is just the warm-up. I let go and Mistress Zora takes over the control of his airways. We train him to build up his stamina while enjoying the silence because he can't talk with our hands over his mouth. We amuse ourselves at his expense! :D