E! illustration/IntimissimiPanty lines showing under leggings? The struggle is very real. Lucky for us, seamless underwear exists, and it promises absolutely no lines underneath your skin-tight leggings and bodycon dresses. Whether you're a cotton-only person or you don't really care about the fabric unless it's soft and lightweight, there's a seamless option out there for you. But where on the internet do adults shop for underwear? Believe it or not, there's a whole world out there. Looking for sexy and soft? Kim Kardashian's Skims is perfect.