Wicked bumper

Butty with attitude - in Jamaica, a female "Tourist Official" asked, if I knew what "a wicked bumper" is: As I toll her I did not know, she explained that Jamaicans usually call a "butty with posture" , resp. "Butty with attitude" a
"Wicked bumper" - interesting: I did not know her expression, so far, nor did she know mine, and so we both agreed to use the other ones in the future...!