DEAN: Yeah, I’m back – and I’m glad to find you not blonde.
RORY: Yeah, I was just having way too much fun, so . . .
Rory refers to the Clairol hair lightener advertising slogan, “Is it true …blondes have more fun?”. It was written by advertising director Shirley Polykoff – a blonde – in 1956, and was considered rather risque at the time.
Rory bleakly jokes that she didn’t dye her hair blonde, because she was already having too much fun (of course she’s actually having a terrible time). Ironically, it is Jess’ girlfriend who is the blonde, and having a lot more fun than Rory.
With his usual ability to turn up unannounced wherever Rory happens to be, Dean has returned home from Chicago three hours early. Although this would have put a serious dent in her plans to be with Jess at the festival, she may be more glad to see him than not, considering that Jess is with someone else, and she’s just had a huge fight with her mother.
Note that even while hugging Dean, Rory is looking over his shoulder at Jess, her face hurt and angry.