LORELAI: It’s as close as you’ll ever come to being a dog.
EMILY: I beg your pardon?
LORELAI: You know, a whole life of nothing but eating, sleeping, lying on your back and getting rubbed.
EMILY: I’d love the comparison to stop there.
Emily probably asks Lorelai to stop comparing her to a dog because she’s thinking the next thing on the list is cleaning her own private areas with her tongue! Or that Lorelai is getting perilously close to calling her mother a “bitch”.
The Annotated Gilmore Girls 