A sister and brother are talking to each other when the 
little boy gets up and walks over to his Grandpa and says, 

"Grandpa, please make a frog noise."

The Grandpa says, 

"No."

The little boy goes on, 

"Please .. please make a frog noise."

The Grandpa says, 

"No, now go play."

The little boy then says to his sister, 

"Go tell Grandpa to make a frog noise."  

So the little girl goes to her Grandpa and says, 

"Please make a frog noise."

The Grandpa says, 

"I just told your brother no and I'm telling you no."

The little girl says, 

"Please .. please Grandpa make a frog noise."

The Grandpa says, 

"Why do you want me to make a frog noise?"

The little girl replied, 

"Because mommy said when you croak we can go to Disney world!"