"Drunk Irish" joke

A man stumbles up to the only other patron in a bar and asks if he could buy him a drink.
'Why, of course,' comes the reply.
The first man then asks, 'Where are you from?'
'I'm from Ireland,' replies the second man.
The first man responds by saying, 'You don't say. I'm from Ireland too. Let's have another round to Ireland.'
'Of course,' replies the second man.
Curious, the first man then asks, 'Where in Ireland are you from?'
'Dublin,' comes the reply.
'I can't believe it,' says the first man, 'I'm from Dublin too. Let's have another drink to Dublin.'
'Of course,' replies the second man.
Curiosity again strikes and the first man asks, 'What school did you go to?'
'St Mary's,' replies the second man, 'I graduated in 1962.'
'This is unbelievable,' the first man says. 'I went to St Mary's and I graduated in 1962 too.'
About that time, one of the regulars comes in and sits down at the bar.
'What's been going on?' he asks the barman.
'Nothing much,' replies the barman. 'The O'Malley twins are drunk again.'