This is no joke.

‘Stranger Things’ star Jamie Campbell Bower, who plays Lord of the ‘Upside Down’ Weekner on the Netflix series, has come a long way since he failed his audition for the hero role in the ‘Harry Potter’ franchise — — if only his penchant for naughty jokes didn’t make him the best.

The 33-year-old actor revealed the mistake while appearing on Josh Horowitz’s “Happy Sad Confused” podcast.

As Ball says, the young actor met with the film’s first director, Chris Columbus, for which he was asked to prepare a joke.

“I just heard this joke about fairies,” Ball recalled.

“Like, the reason why fairies sit on the Christmas tree. It’s really a very dirty joke because it’s about someone’s ass with a Christmas tree.”

The “Twilight” series star went on to describe how embarrassing things have gotten after the punchline failed.

“I told the joke in the audition, and after I said it, there was this silence. I was like, ‘Okay, f-fuck it up,’” Ball joked.

Although Ball lost his title to Daniel Radcliffe, Ball managed to appear in Harry Potter and the Deathly Hallows: Part 1 as a young Gellert Grindelwald in franchise, and again in the spin-off Fantastic Beasts: The Crimes of Grindelwald. ”

According to his agent Lindsay Simon, he apparently cleaned up his act when he took on the role of the Dark Wizard, and he promised he would return to the wizarding world.

“Simon said, ‘Okay, Jamie [is] Now, you know, working fine and not telling too many rude jokes,” joked the actor.