You know it's a big deal when funny man Will Ferrell is upset. 

When the star went on "Conan" to plug his latest comedy "The Campaign," he was overwhelmed with grief from hearing about the romantic rupture between the adulterous Kristen Stewart and her jilted "Twilight" co-star Robert Pattinson. 

Through heavy tears, Ferrell laments that "they were in love...and she just threw it all away!" After worrying about the future of the "Twilight" franchise, he even blames himself before lashing out at Conan for not understanding.

The coup de grace is Ferrell's accusal of Stewart being a "trampire."

It may be his best performance yet. 

Watch the clip here.

Meanwhile, according to Variety, Ferrell has signed on for a cameo in "The Internship," which will reunite him with frequent co-stars Vince Vaughn and Owen Wilson.

The three comic actors also appeared together in "Wedding Crashers," "Zoolander" and "Starsky & Hutch," with Ferrell and Vaughn co-starring in "Anchorman" and "Old School."

Ferrell will soon be seen in "The Campaign" with Zach Galifianakis, while "Anchorman 2," featuring Ferrell and Vaughn, will begin shooting soon.