Every body is different even if they wear the same size. There is a slightly bigger medium and a slightly smaller medium. You could be a large at the beginning of the month and a medium at the end of the month. Now imagine bras and panties that move and stretch every time you do. At LoveSuze, we design, with a flex-sizing mindset, underwear that comes in dual sizes and is flexible in how it stretches and adapts to a woman's body.