 Women 's swimwear of the 1930s and 1940s incorporated increasing degrees of midriff exposure . Teen magazines of late 1940s and 1950s featured similar designs of midriff @-@ baring suits and tops . However , midriff fashion was stated as only for beaches and informal events and considered indecent to be worn in public . Hollywood endorsed the new glamor in films like Neptune 's Daughter in which Esther Williams wore provocatively named costumes such as " Double Entendre " and " Honey Child " . 
