LOUISE: [referring to Dean] So how good of a kisser is Paul Bunyan anyway?
Paul Bunyan is a giant lumberjack from American folklore, apparently originating in the oral tradition of 19th century North American loggers, but spread via advertising campaigns for the logging industry in the 20th century. Tremendously strong and skilful, Bunyan is often depicted with Babe the Blue Ox as his companion. Paul Bunyan stories became very popular in children’s literature and entertainment.
Louise is making a comment on Dean’s height, but as Paul Bunyan is meant to be from New England and often associated with the Midwest, he is like Dean in having connections to both these regions.