I had an Irish room mate from Boston my first year of college... Let me tell you - don't get in the way of an Irish man and his beer/liquor... That's grounds for a fight...
However, buy them a beer or whiskey and you make a friend....
He would stay at the frat parties until the keg ran dry... He stumbled in at 9 or 10 AM the next morning many times after a frat party... Then would tell me to make sure that he's awake by 5 or 6 that evening for the next party...
He had a large beer mug that could hold two beers and would hold it with both hands so it wouldn't spill when people bumped him trying to pass by at a full party... He would hold it with one hand on the bottom and one hand on the handle...