On a recent promotional stop for 'The Campaign' stars Will Ferrell and Zach Galifianakis got a little goofy with "mommy porn" novel 'Fifty Shades of Grey.' Watch the comedic pair read excerpts from the wildly popular -- and wildly terrible -- novel.

Will Ferrell and Zach Galifianakis were doing interviews for 'The Campaign' this week when a clever reporter decided it might be fun for them to take turns reading from 'Fifty Shades of Grey,' the bestselling novel (read: 'Twilight' fan fiction) about a young woman who falls for an older man with a BDSM fetish.

The video seems a bit silly at first, and even Ferrell and Galifianakis appear to oblige just to be polite, but then they actually start reading from the book and things get pretty hilarious. Neither of them can process what they're reading as they're saying the words aloud, and both get confused as to what parts they should be speaking. The scene in particular takes place in a bath tub, though Galifianakis wonders if they're in a kiddie pool.

If you're not up to date with the 'Fifty Shades of Grey' phenomenon, we broke it down in a handy article a few months back. Or you could just watch the video below and get a pretty good idea of how horribly written this stuff is, but it sounds so delightful coming out of the mouths of two comic geniuses.

You can check out more of Ferrell and Galifianakis' steamy on screen chemistry when 'The Campaign' hits theaters on August 10.