Many years ago I made the mistake of asking for a Black & Tan in a pub in Dingle. The bartender looked confused asked me what that was (in a loud voice to draw in the other customers), because, of course, he'd never heard of it, he claimed. I'm sure he had, but this was a great opportunity to have sport with a Yank, so I then had to lamely explain it was half lager and half Guinness, which gave him the opportunity (in a voice loud enough to draw the attention of everyone in the bar) to make it while complaining about "why dint I just piss in my porter instead of pouring lager in it..?" and similar helpful commentary. This was all delivered with that unique Irish charm of telling you what a special 'idjit' you are with a big smile and colorful commentary on my parentage, relative thickness ('tickness' in brogue), and generally poor prospects of ever advancing beyond my current state of hapless ignorance. All of that with a big smile and sympathetic tone, because he's just trying to help... In short, they don't care for people who dilute their porter with lager. If you want to drink lager, fine. If you want to drink porter, even better. Only idjits mix them together. .
At that point, you tell him to ram his pub right up and go somewhere else. Or maybe I'm just a troublemaker.
There was only one pub in Dingle, and one restaurant, and one hotel. And the guy was just having sport, and later told me how he'd taken the piss out of Robert Mitchum when they were filming Ryan's Daughter there many years before. The proudest moment of his life. He also told me how his father had helped capture a German spy in the pub in WWII. He had come ashore from a submarine under the eyes of a dozen nearby farmhouses residents, presumably to wend his way into GB. He made his way to the pub where he enjoyed some beer and asked about the bus. Meanwhile, the local Gardai officer, who had been informed of the spy and the submarine by half the village, was driving to Tralee (maybe an hour away) "to get the gun." When he got back, the German was thoroughly drunk and offered no resistance. I suppose he ended up in one of those Irish internment camps and was able to enjoy a lot of Irish beer for the rest of the war, because the Irish allowed interned prisoners from both sides to take daily excursions to the local villages. War is heck... . . .