"Oh man, I've stopped trying to analyze it, because it makes me upset," the actor, 26, tells GQ's April Style Bible of his "douchebag" roles. "Once I was complaining about it to someone, and they said, 'It's because you have an asshole face.' I was like, 'Um, thank you. Thank you very much.'"
Dave -- who stars alongside Channing Tatum and Jonah Hill in 21 Jump Street -- also gets uncomfortable thinking about his infamous Funny or Die sketch "Go F-ck Yourself."
"When people bring it up now, I get bashful, because it's like you've literally seen me have sex with myself," he says.
Like his older brother James Franco, 33, Dave has also dabbled in poetry.
"My God, it was really pretentious sh-t," he tells GQ's April Style Bible. "I would write a poem out in the most simple terms, and then I would go through the thesaurus and find these elite replacements for them."