If you saw the trailer, you know that in Mr. Brooks, Kevin Costner plays a successful business man who kills for pleasure. He wants to stop but he just can't: William Hurt (who plays Kevin's alter ego -- they talk to each other like there's no tomorrow) keeps convincing him to continue killing.
Dane Cook watches one of Kevin's jobs and starts to blackmail. Demi Moore is a millionaire cop (yes, a millionaire cop) who wants to put an end to it all.
There was a tiny bit of gay content: in one scene, Dane Cook is reading this note that must be read by putting together words that had been circled on a newspaper, and one of the circled words is "same" on a headline that says "Same-sex Marriage" -- that was nice (although we can't really read what the article under the headline says).