LORELAI: Uh, well, I’ll have a white wine and Dean’ll have a beer.
LORELAI: Corona, right?
DEAN: No, I don’t want a beer!
Corona Extra is a brand of Mexican pale lager produced by Cervecerio Modelo, first made in 1925. It is the top-selling imported beer in the United States.
All three Gilmore females take a slightly malicious pleasure in torturing Dean by pretending that he wants to drink beer. It’s a callback to the night of Rory’s winter formal, when Emily questioned Lorelai about Dean, including asking if he drank.
You can’t help feeling there’s a bit of payback for accidentally keeping Rory out late on the night of the dance, which led to an almighty family row. You can see Rory as either joining in with it, or trying to defuse the situation with humour.