To simulate a bubble gum bubble with the scrotum and a testicle.

To blow a bubble:
1. make a circle with your thumb and index finger, a little smaller than the size of a testicle
2. Pull some skin of the scrotum through the hole, so it hangs loose from the hole (be sure not to grab the testicle too)
3. With your other 3 fingers, slowly finesse the testicle through the hole utnil it pops completely through, filling the skin, resembling a bubble gum bubble.