These pants run very true to the measurements listed. I have a 27in waist and 40in hip/butt -- the small fit my waist perfectly, but is skin-tight in the hips/butt. The material is double lined (it's a soft, kind of fuzzy material on the inside), so even though it's very tight, nothing shows through. It's also very stretchy so you can move and kick around with no problem. I will say, when you first put on the pants, air does get trapped in the crotch area so you kind of have this air bubble until you start moving around.