"The irish are friendly civilised people and though they support their county with zeal, they never abuse their rivals through song."

From the Ireland section in the there's a hint that once soccer comes in the door all that can fly out the window. (Though it's true enough for Gaelic Football and Hurling). Here's one from Glentoran:

In your Portadown (or Shankill Road) slums (where?)
In your Portadown (or Shankill Road )slums,
You hoak in your dustbins for something to eat,
You find a dead rat and you think its a treat,
In your Portadown (or Shankill Road) slums.
Where?
In your Portadown (or Shankill Road) slums
Your ma is a whore and your da shags the sheep
You're the dirtiest bastards I ever did meet
In your Portadown (or Shankill Road) slums.