Tongue-in-cheek phrase appears in 1828 in "The Fair Maid of Perth" by Sir Walter Scott: It's not clear how Scott intended readers to understand the phrase. The more modern ironic sense appears in the 1842 poem "The Ingoldsby Legends" by the English clergyman Richard Barham, in which a Frenchman inspects a watch and cries: The ironic usage originates with the idea of suppressed mirth—biting one's tongue to prevent an outburst of laughter. Tongue-in-cheek The idiom tongue-in-cheek refers to a humorous or sarcastic statement expressed in a mock serious manner. The phrase originally expressed contempt, but by 1842 had acquired its modern
How to Be a Woman This same connotation comes with 'breasts', as well. Moran talks about how "breasts" isn't anyone's first choice and also how 'boobs' largely refers to "white and working class" and "exist only to jiggle up and down on the chests of women between the ages of 14 and 32". Caitlin continues contemplating other breasts nicknames and how they are or are not appropriate. Ultimately she settles on this; "The English language has yet to get its head convincingly around the problem of the average woman's [breasts]" and vagina, but the use of appropriate language is an individual's personal choice. Deciding to