In come three flies, and plink, plank, plunk!, drop into the three beers.
The Englishmans says "Eeeeewwww!", and pushes away his beer.
The Irishman reaches in, grabs the fly, flicks it away, and resumes drinking.
The Scotsman reaches in, grabs the fly, shakes it, and says "Spit it out, ya wee bastid!"