'Dancing With the Stars' vs. 'X Factor': Who rules the toilet?

We weren't kidding with that headline.

"Dancing With the Stars" and "X Factor" both tape their shows at CBS Television City in Hollywood, and it seems that the competition shows are getting a little... well, competitive.

TMZ posted the above photo from the door of the bathroom on the stages. Apparently, a "Dancing With the Stars" staffer wasn't too pleased when "The X-Factor" plastered their logo on the door.

An "X Factor" spokeswoman tells the NY Post, "Please tell Rob he's welcome to use our restrooms anytime!"

These people need to spend some time on PassiveAggressiveNotes.com.