Ariana Grande and Elizabeth Gillies had quite the reunion!

On Monday, the 22-year-old singer posted a video of herself and her former "Victorious" co-star, who currently stars on "Sex & Drugs & Rock & Roll," sharing an intimate moment before they break out in a fit of laughter. "It has to be pretty, though," Gillies tells Grande before they lock lips.

"My favorite video of all time," Grande captioned the video of the two girls kissing. "(p.s. this was totally posted by accident)" She also tweeted an explanation, saying that she was just editing it on Instagram, but instead, accidentally posted it. "But its great so whatever," she wrote.

The two have remained good friends ever since they got their big break in the 2008 musical "13." They then went on to star on the hit Nickelodeon show "Victorious" together from 2010 to 2013, and are one of the few children stars to not have a falling out.

"She's like blood to me, she's like my sister," Gillies told People back in June. "So unless we have a massive falling out, nothing will be happening there. We lived together, I've known her since what feels like the beginning of time."