I designed the Split Shorts in my “Sew Your Own Activewear” book to have the greatest mobility possible to minimise the chance of the inseams riding up while running (a really common issue with running shorts!). These shorts do show a bit of thigh, but the back of the shorts stay close to the body, and the inseams really do stay put. In fact, they can be mistaken for a skort or running skirt while you’re in motion, and they look really feminine!
But some of you may find that the Split Shorts as drafted in the book are a little more revealing than you’d like, and the good news is that there are two easy ways to adjust for this! Note that by making these less revealing, though, you are limiting the mobility of the leg, so be sure to make incremental steps and sew and test your muslins along the way to make sure you can still move effectively in them. But if you’re planning to wear these for an activity that doesn’t require the extreme amount of forward leg motion needed for running, then modesty may be more important to you than the range of motion anyway!