In S1E15, Lorelai is describing to Christopher why their evening at her parent’s house had been terrible. She says, “My father almost hit someone! My father has probably only hit a man in college, wearing boxing gloves and one of those Fred Mertz golden gloves pullover sweaters.” Christopher repeats, “Fred Mertz?” Lorelai confirms, “I Love Lucy, Fred Mertz.” Christopher, offering us a brief glimpse into why he and Lorelai ever worked well together, responds quickly, “Landlord to Ricky, husband to Ethel, I know. It’s just a weird reference.”
Fred Mertz is a character, played by William Frawley, from the 1951 television show “I Love Lucy.” Fred is, as Christopher says, Lucy and Ricky’s landlord. His wife is Lucy’s best friend Ethel. Fred is known to have been a boxer in his younger days, and he does indeed wear a golden gloves sweater in one episode.