The snug, hip-hugging fit is everything, but it can also be your worst nightmare. Cases of butt acne—or “buttne” as it’s called—are on the upswing these days, and your yoga pants might be to blame. Dr. Dhaval Bhanusali, board-certified dermatologist and Skincare.com consultant, admits to seeing patients with this concern about three to four times per week. “It definitely is pretty common,” he says. Talk about a pain in the butt. Here’s how it works: You put on your yoga pants in the morning for a killer workout class where you work up a major sweat. Since the pants have a tight fit, the friction causes sweat to be continuously rubbed into the pores. Throw bacteria into the mix and you have yourself a little pimple party brewing on your bottom. Now, imagine sitting in those sweaty pants for the remainder of the day. Some ladies don’t even bother washing their pants between multiple uses. Pretty gross, right?So, do we have to toss all of our yoga pants into the bin and never look back? Not really. The moral of the story is that our yoga pants aren’t to blame so much as our negligence of proper hygiene when wearing them. Intersperse your spandex pants with loose-fitting clothes that allow your skin to breathe. If possible, limit wearing your yoga pants to periods when you’re actually exercising. When you’re done working out, “change your pants immediately and take a shower,” Bhanusali says. If you already have zits on your butt, Bhanusali recommends visiting your dermatologist and resisting the urge to pop those pimples, as it can lead to infection or scarring. And for the love of skin care, wash your yoga pants after wearing them just once!