Jennette McCurdy reveals what made her forever ‘pissed’ at Ariana Grande

The “Sam & Cat” claws are out.

Jennette McCurdy says her dislike for Ariana Grande began soon after they started filming their Nickelodeon show when she realized the pop star allegedly got permission to pursue outside opportunities.

“I booked two features during ‘iCarly’ that I had to turn down because the ‘iCarly’ team wouldn’t write me out of episodes to go shoot them,” McCurdy writes in her new memoir, “I’m Glad My Mom Died,” claiming producers would stuff Grande’s character in a box so that she could miss filming.

“Are you. Kidding me,” McCurdy recalls thinking. “So I have to turn down movies while Ariana’s off whistle-toning at the Billboard Music Awards? F–k. This.”

The “Best Player” actress, 30, admitted that once Grande, 29, was allowed to ditch filming, she snapped.

“I’m pissed about it. I’m pissed at her. Jealous of her. For a few reasons,” she writes. “So now, every time she misses work it feels like a personal attack. … From that moment on I didn’t like her. I couldn’t like her.”

“iCarly” ended its original run in 2012, and “Sam & Cat” ran just one season from 2013 to 2014.

A rep for Nickelodeon never returned Page Six’s request for comment.

Grande has not publicly responded to the excerpts from McCurdy’s memoir.

The rest of the “Zoey 101” alum’s book is filled with heartbreaking anecdotes about her battle with bulimia and her strained relationship with her mother and Nickelodeon.

McCurdy writes that after departing the kids’ entertainment network, she turned down a $300,000 offer that would require her never to speak publicly about her experiences there.