Justin Bieber is a very busy pop idol these days—he's touring all over and promoting Purpose.

So its understandable he wants to get away from it all, like he is now—camping with friends at the Grand Canyon.

And sleeping under the stars.

All that fresh air can make a man want to run around naked—hey we've all been there.

In the adjoining caption, Bieber wrote "dat ass doe." (Well, maybe if the camera zoomed in a little closer we could tell.)

In truth, though, Bieber mooning Instagram is something of an annual affair. In 2014, he flashed his tush at pal Lil Za.

And last July, he posted a rear nude on a boating trip.

You'd think a butt that sees that much sunlight wouldn't be so pale.