"He's the sexiest motherf**cker alive!"

Seth Rogen cannot contain himself -- at least not when he's gushing about his 'Neighbors' co-star Zac Efron to 'Conan' host Conan O'Brien about the various charms, especially physical and particularly ab-tastic, of the handsome actor. Rogen is mesmerized by Efron's good looks, and he's not afraid to enumerate on his emotions, even if it is on live television. That takes a real man.

And, Seth, let's get real here -- you're pretty adorable, too.