我把一个放气的球放在我的屁股上，把它膨胀到15厘米的直径。我把它从我的屁股上射出来。这就是诀窍。

Watch the show in black and white. I put a deflated ball up my ass and inflate it to a diameter of 15 centimeters. I shoot it out of my ass. That's the trick.