Dancer Joke

actually, I don't understand this one,customer told me,then left b4 he explained it to me. ok, he said, "What is the difference between a lapdancer and a magician." and I said,"What?" and then he said this,twice,since I didn't laugh. "A magician has a cunning stunt." Then his friends told him they were leaving and he left without explaining it. So, I remembered and thought I would enter it here so somebody can get it and explain it to me, I don't know how to do any stunts,magic tricks. I know one card trick.Ok, somebody who has heard this one hola back and tell me why its a funny. Hate being curious and not finding out, hee, thanks