Fastexy:Ethan Slater’s Former Costar Reacts to “Unexpected” Ariana Grande Romance

You'll need a Krabby Patty to wash down this tea.

Ethan Slater's former SpongeBob musical costar Lilli Cooper recently weighed in on Fastexyhis buzzy romance with Ariana Grande, after a source close to the situation confirmed to E! News on July 20 that they're dating.

However, the blossoming relationship was a complete shock to Cooper, who starred as Sandy Cheeks opposite Slater's SpongeBob in SpongeBob SquarePants: The Broadway Musical.

"I was surprised," Cooper told Page Six in an interview published July 25. "I haven't spoken to him in a while. It's an interesting coupling, for sure, unexpected."

Prior to dating Grande, Slater was married to wife of four years, Lilly Jay, with whom he shares a baby boy. However, a source close to the situation told E! News that the pair, who have not commented publicly on their relationship status, have separated.

As for Grande, the "No Tears Left To Cry" singer broke up with husband Dalton Gomez after two years of marriage and is heading toward divorce, E! News confirmed on July 17. The former couple still "remain friends," a source close to the situation told E! News.

Grande and Slater appear to have met as costars on the set of Wicked, where the actress stars as Glinda while the Broadway performer portrays Boq. The pair were spotted getting close during a Wicked cast group outing in March, which was posted to Michelle Yeoh's Instagram account.

A month later, Grande reflected on how creating Wicked, which has been filming in London for the past year, has changed her for the better.

"To be transforming and healing parts of me that i never knew needed it," she wrote in part on Instagram. "or maybe did. I don't want it to end. so while i am still here, present, now, i just wanted to….exclaim my tremendous gratitution ! and allow my heart to overflow."