It's the final condom

The story:

This wasn't me, it was a French guy, by the name of Greg, who is friends with my colleague, Seamus.

Greg was visiting Seamus in Ireland, and the pub they were in started playing this song. He began singing "it's the final condom!", at the top of his lungs, until everyone's initial surprise turned to general berating. He had been singing the lyrics that way since before he learned English

Of course, they've all copied his lyrics ever since. I feel it gives more power and urgency to the delivery of the lyrics.