When Rainbow agreed to accompany Twilight on a lonely day trip, she hadn't anticipated the terrible luck she'd have finding bathrooms, but the element of Loyalty would never leave a friend hanging. Unfortunately, a broken outhouse at the end of the track appears to spell her doom. Only some quick thinking from her friend and a convenient garbage bin can save what little remains of her dignity.

Based on some great art you can find here: https://derpibooru.org/images/1812250?q=artist%3Aithinkitsdivine