I/we had to laugh at a mouthy fan once (not quite a heckler, but similar), at a Lee Mack show. It was at the Sheffield city hall and the fan in question was actually a Wensdy fan lol. Mack kept stopping and giggling, and eventually he shouted to him.. " listen mate, do you want to come on stage and take over, because your getting more laughs than me at the moment! ".