Oh, I have this really cute pick-up line:
Take his/her hand in your hand and draw a line with a pen, this is the river. Then draw a cute little bunny on the other side. "So the bunny wants to get to the other side, how does he do it?" Let them guess... make up witty reasons why the bunny cannot do it that way. Then when they finally give up, "I don't know, I just wanted to hold your hand."
Adorable, and lasting. They'll have to wash that off to forget you.