little girl and her grandmother Joke

This little girl walks over to her grandmother and asks "Granny, can you show me a magic trick?" "No dear, but I think your grand father knows one." So the little girl walks over to her grandpa and asks "Grandpa, granny says you know some magic tricks, could you show me one?" The grand father looks at her, "Sure, just hop on my lap!" So the little girl jumps on his lap. "Now, can you feel a finger poking up your ass?" asks the grandpa, "Yeah" replies the girl "Well look, no hands!"