There is a bit of kid in us all and I find this endlessly amusing. As kids, my brother and myself would running around saying 'bum', laughing our heads off because we thought it was such a rude word.
Here is my present day equivalent. There is movie out at the moment called 'Meet the Fockers'. Surely a title you need to be careful with. Normally I would not see a movie like this but here is why I want to see it.
The mother's character name is Martha.
If there is more of this sort of word play, I really want to see it.