Found a joke feed but not telling you what it is

One day an Englishman, a Scotsman, and an Irishman walked into a pub together. They proceeded to each buy a pint of Guinness. Just as they were about to enjoy their creamy beverage, three flies landed in the pints, and were stuck in the thick heads.

The Englishman pushed his beer away from him in disgust.

The Scotsman fished the offending fly out of his beer and continued drinking it as if nothing had happened.

The Irishman picked the fly out of his drink, held it out over the beer and then started yelling, "SPIT IT OUT, SPIT IT OUT YOU BASTARD!!"