We know it's 'X Factor' time again when Demi Lovato and Simon Cowell start going at it -- on Twitter, during tapings, you name it.

The two sole remaining judges from Season 2 bicker endlessly on the show and via social media, but we're going to give Lovato the upper hand, as she drudged up embarrassing photos of Cowell from ages ago, leaving him begging for mercy. They are that embarrassing for Cowell, and hilarious to anyone who takes a peek at them.

Lovato shared shots of Cowell with a crop of big, messy hair, wearing that same familiar scowl. Cowell is also rocking the tight T-shirts he is known for today. Apparently, it's been his signature for quite some time.

We've gotta hand it to her. She really put the social media screws to the acid-tongued judge!

We do feel compelled to issue this warning, though! Paybacks are a b----, Demi. We bet Simon is already planning his just desserts. Look out, girl.

Check out her tweets below, and of course, Si Co's tweet pleading with her to be kind and stop sharing the pics! We almost feel sorry for him. Almost!