A 'Poppleton’ is when someone, no matter how cool or sophisticated they are, always manages to do something outrageous and/ or stupid. They are regularly seen with a guitar, bottle of coke and a mars bar in hand and regularly sleep with rotters.
"oh no, look at that rotter he is going to bum, he had definately pulled a poppleton"
"Banned from the road for drunk driving? that is very poppleton"