Up One's Sleeve

Up One's Sleeve 

All right, Sara. We know that you're planning something big for Jean's birthday. Mind telling us just what you have up your sleeve

I wanted to make his birthday a very special event 

Jean has a sister living in France, and I sent her an airplane ticket so that she could be here for his birthday

Boy! That is something special. We kind of guessed that you had some concealed plan and were waiting for the right time to reveal it 

Well, I didn't want to say anything until I was sure she could come