MAX: Well, well, well.
LORELAI: What’s up, Teach?
Probably a play on “What’s up, Doc?”, the famous catchphrase of Bugs Bunny in the Warner Brothers cartoons. It was first used in the 1940 animated film A Wild Hare, and director Tex Avery chose it as a common phrase used at the time in his native Texas.
It’s also very possible Lorelai is thinking of the film What’s Up, Doc?, a 1972 screwball comedy directed by Peter Bogdanovich, and starring her favourite, Barbra Streisand. The #3 movie of 1972, it is considered one of the greatest comic films of all time.
The movie ends with the lovers kissing as they watch the 1950 Bugs Bunny film, What’s Up, Doc? Maybe Lorelai is already thinking of kissing Max at the movies, as she is just about to take him to one.