I was working today - I'm a volunteer at a charity shop - and this guy walked up to the counter, so I put on my "smile at the customers" face. Our conversation went as follows:
Him: Ah, service with a smile, that's always nice to see.
Me: *smiles back*
Him: Don't worry, I won't ask for you phone number.
He looked about 28-ish, I'm 14

I was amusing, I guess.