Our classic Fernando low rise brief now has a reinforced athletic elastic inside the double-stitched leg trim.  This helps lift your butt and keeps the brief from riding without ever losing its form.  Please note that the Fernando's contour design hugs snuggly to your body accentuating your best assets in true brazilian-bikini fashion.  As such, IF YOU ARE TRYING TO DECIDE BETWEEN SIZES, we strongly suggest you go one size up.