sounding more like bad italian rather than yardie though...
I think the original version was Italian, of which there are a few variations as well. Here is one
A bus stops and two Italian men get on. They seat themselves, and engage in animated conversation.
The lady sitting behind them ignores their conversation at first, but her attention is galvanized when she hears one of the men say the following:
''Emma come first. I come. Dennis come and Dennis come again. I come again. Two asses, they come together again. I come again and pee twice. Then I come once-a-more.''
''You foul-mouthed swine,'' retorted the lady indignantly. ''In this country we don't talk about our sex lives in public.''
''Hey, coola down lady,'' said the man. ''Imma just tella my friend howa to spella Mississippi.''
or
MISSISSIPPI! Emma come first. Den I come. Den two esses acoma together. I coma once-a-more. Two esses, they comma together again. I come again and pee twice. Then I come one lasta time.
