I used to do something similar many, many years ago. I used to walk in to ASDA with an unlit fag in my mouth. The security guard would always shout 'No smoking'. I'd shout back 'I'm not smoking'. Mrs Mottie said I was being petty.I used to take them for a ride outside tube stations.
I would walk about up and down with a fag and the fools follow every step.
Then I'd pretend to flick the butt on the pavement and they'd approach at the speed of light.
I let them talk their caper and then show the butt still lit in my hand.
Their jaw dropping to the floor makes a nice sound