An Irishman walks into a bar in London , orders 3 pints of beer and sits in the back of the room, drinking a sip out of each one in turn. When he finishes, he comes back to the bar counter and orders 3 more. The bartender tells him, ""You know, beer goes flat after I fill it in the glass; it would taste better if you buy one at a time."" The Irishman replies, ""Well, you see, I have two brothers. One is in Dublin , the other in Canada and I'm here in London . When we left home, we promised that …