'Harry Potter' Stars Tom Felton, Matthew Lewis Has Twitter Duel Loved By JK Rowling! Who Won?

They may be enemies in the "Harry Potter" saga but Tom Felton and Matthew Lewis, along with the other cast members of the successful film series, are actually friendly with each other behind the scenes.

Despite being a Slytherin in the movies, Felton has been constantly spotted hanging out with other Gryffindor "Potter" actors in real life. That doesn't mean that they can't bring out their onscreen rivalry off screen from time to time.

Tom Felton and Matthew Lewis recently had a Twitter duel about their Hogwarts houses and their fans weren't the only ones who enjoyed the pun-y exchange. JK Rowling, who wrote the "Harry Potter" books, tweeted about the duo's friendly competition and she definitely loved every minute of it.

According to RadioTimes, the exchange started when the Felton, who played the snotty Draco Malfoy, tweeted the trailer of his new movie, "Risen," where he plays a Roman soldier during Jesus' death and resurrection, last week.

Lewis then showed his support by telling his followers how "psyched" he was for his pal. This led to Felton revealing an apparent golf game that they were having soon, adorably calling Lewis his "brother."

"Ready for a crushing defeat?? #Gryffinwho?" he posted.

Being the Gryffindor that he is, Lewis didn't simply bow down in defeat.

"Leave it out. We've got plans for you boys. You're gonna get Slytherinsed," he replied.

The hilarious conversation caught JK Rowling's attention and she promptly took posted a proof shot of it.

"So proud of my boys," she captioned the photo she posted on Twitter. "Even after all these years, they still want to kick each other's arses."

Based on Felton's recent tweet, his Gryffindor friend lost the game.

"Incase you're all wondering, this team captain won! Sorry mate @Mattdavelewis #slythewin," he posted along with some photos of the both of them and a few others with their teams.

Tom Felton and Matthew Lewis' Twitter duel isn't the first time that the writer noticed "her boys" on social media. She previously called out Lewis' very sexy photoshoot for Attitude magazine in May. "Not as bad as watching Dan in Equus, but close. Warn me next time, for God's sake," she tweeted the actor, to which he quickly apologized.