I have a cunning plan, go through the turnstyles with your mates make sure one of your mates is a junior swop the junior ticket with an adult ie your mates who have got through just inside the turnstyles, make sure he goes through last, if he is pulled say ho sorry the cards have got mixed up. Take the junior to the the operator with the adult, Worth a try as a back up, they might tell you to bugger off but they just might buy it?