Mint Green High Waisted Shorts

Mint green high-waisted shorts, mint green zipper on the side. Very flattering, very soft and comfy. I wore it maybe twice but it doesn't fit my butt anymore! It doesn't have pockets and it's thin, not bulky at all. It says Medium but I listed it as a Small b/c that's my usual size and it has a snug fit. If any measurement questions, pls lmk!