Two guys upstairs on a double decker bus

the first guy says to his mate No you have got it spelled wrong!
Its spelt WOOOM

Is friend disagreed he said no your wrong its spelt WOOMBE

This argument went on for about 15 minutes with different suggestions on the words spelling.

I rather large lady sat in the seat in from of the two guys had been earwigging the conversation and she turned round and said to the two guys that they were both wrong and that the correct spelling was WOMB.

The two guys looked astonished that someone could have the nerve to interupt their conversation and the first guy said listen Misses you have know idea what we are talking about. So mind your own business.

The lady enquired what were they discussing then.

The other gur replied that they were talking about what sound a hypopotemous made when it farted under water and that they had know idea what she was on about.