Two new young and muscular straight boys are introduced to the Master, eager to try out the experience of being spanked on their butts, for the first time. The Master wants to see their muscles at work and so has them work out with some heavy gym weights first. Then the first boy receives a painful training punishment, he is spanked by hand while over the Master's knee. Afterwards the second muscular straight guy also receives a painful training punishment of a hand spanking, also while over the Master's knee. The casting of Petr and Kuba continues as they submit to even more vigorous and painful spankings by hand. Then the Master decides that some more muscles at work is needed and so has them work again with the gym weights, but this time while naked and with their buttocks still red from being spanked.