This is totally HUGEEEE in Jamaica. Everyone thinks this is the funniest thing ever. I posted a bunch of parodies videos.
"Twanging" is a derogatory term for when a Jamaican who grew up speaking heavy patwa (the basilect, if you wanna be all kinda-awkward-colonial-overtones-linguist about it) tries to "clean up" his English to make it sound more British/proper (and fails). I found this very awesome post on a dancehall forum about it, copy/pasting here:
"There's no psycholinguistic basis for a grown-ass adult to be twanging like an idiot after living somewhere for a few years. Children yes, adults hell no. If you spent your formative language-learning years in the Caribbean and moved abroad anytime after your late teens, your vowels should be fully-pronounced and each consonant enunciated. No t/d consonant shifts. No unstressed mid-central vowels. No lengthened diphthongs. If yu ask mi fi "peyass tha budder" mi a guh ask yu wha di bumborassclaat name budder an wha di rass yu really waan mi do to it.
If you couldn't speak English properly before emigrating, pay close attention to the following sentences. The accent you hear the white people around you using is not part of the language. Imitating it doesn't make the mealy-mouthed shit emanating from your mandibles real English. "Hoi were livin' in Birming 'am four tree ears" is not real English. Putting a British, Canadian, or American cherry on your verbal diarrhea milkshake doesn't sweeten the goddamn flavour."