Don Lemon, left, and Jonah Hill. Credit: Robin Marchant|Niki Nikolova/Getty Images.

Don Lemon and Jonah Hill are immersed in the kind of feud that would be better played out in a high school hallway than on Twitter.

On Thursday, 46-year-old CNN host tweeted that he said "hi" to the 28-year-old "21 Jump Street" star in a hotel and - gasp - Hill didn't say "hi" back. "Said hi to Jonah in a hotel," Lemon wrote. "Think he thought I was a bellman. Didn't know his name til the bellman told me. A lesson to always be kind." In another tweet, Lemon said Hill "was a tool."

Hill later responded, "I said hi. What do you want me to do, move in with you? I was in a hurry. Didn't realize you were a 12 year old girl. Peace."

Lemon wrote back, "Hardly. You're not my type. But I know rude. And u were."

Hill then explained, "I walked out of the restroom and found you waiting for me. Shook hands, said hi and was on my way. Sorry if you found that rude."

Back to Lemon: "The bellman and I laughed at how self-important you were. Just being honest. Be nice. Stardom is fleeting."

So are tweets. Hill has deleted his entire share of the exchange, only two of Lemon's tweets remain. Lemon also used the attention to plug CNN's morning show, "Starting Point with Soledad O'Brien." Wonder what Donald Trump has to say about all this?

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