Skinny jeans will never go "out," and that's a fact. Just take a look at any one of the handful of celebrities who seem to cling to the perennial denim staple. Season after season,

we turn to these style stars to inform us of the freshest ways to style our skinnies, and according to them, all signs point to one boot trend in particular—riding boots—that just so happen to pair flawlessly with classic skinny jeans.

Kate Middleton has long been a fan of these flat, knee-high boots, and there are plenty of her outfits to get inspired by. They also happen to be approved by Mary-Kate Olsen. (When MK and Ashley wear something cool, you know we're quick to follow suit.) We spotted riding boots all over the F/W 21 runways from a whole host of brands, such as Brandon Maxwell, Celine, and Tory Burch, so if you're looking to get in on the trend, there's certainly no lack of options. Keep scrolling to see how Middleton and Olsen wear riding boots, to see how they're styled on Instagram, and to shop the equestrian trend for yourself.