LORELAI: They just force someone on you?
RORY: It’s all part of the socialising experience.
LORELAI: What if it’s a lemon?
RORY: Then I’m stuck with a lemon.
LORELAI: Hare Krishna banging a tambourine all night?
RORY: Then I have to get earplugs.
LORELAI: Serial murderer?
RORY: Then I sleep with a gat strapped to my ankle.
In American slang, a lemon is a worthless person or object. It dates from the early 20th century, and was originally criminal slang meaning “loser, simpleton” – perhaps with the idea that they were people that the criminal could “suck the juice from”.
In American slang, a gat is a gun. It is short for Gatling gun, the early machine gun invented by Richard Gatling for use during the American Civil War. The criminal slang was especially prevalent during the Prohibition era of the 1920s.
It is perhaps apt that Rory and Lorelai use criminal slang while trespassing.
In a later season, Rory does indeed get a college room mate forced upon her unexpectedly.