Now lie on your back, pass your legs over the pack, let them rest on top of the DVD / book so that they are above the top of the "package".
Now gently return to the sitting position, and crush those balls for good, you will have to sit on your balls again, but this time will be harder.
Keep your leg in tension so that the shoelace is in tension and pull the balls down, do not let them escape from the gift bag haha.
try to stay upright, put on all the weight of the body.
Try to resist as much as possible, try for 2 minutes ...