You can also enlarge the testicles by "ball pumping", which is the use of a vacuum tube to enlarge the testicles by placing the scrotum in a tube and creating a vacuum much like "cock pumping". This swells the testicles with water from the body. It is not dangerous, like scrotal infusion, because there is no introduction of a foreign object (no needles, breaks in the skin, etc.). The sensation you get from pumping is a pressure in the testicles, like a squeezing or pulling, but not uncomfortable. You can feel the increased weight of your balls as they hang. It is very stimulating, and increases the flow of precum while producing larger that usual ejaculations. The effect is temporary unless you pump repeatedly over time. Your testicles can grow from plum to grapefruit size with practice.
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Enlargement by pumping