New York, New York - Ariana Grande celebrated Halloween night on Broadway to support her rumored boyfriend and Wicked costar Ethan Slater, as his revival of Monty Python's Spamalot musical kicked off!

Slater is currently starring in the Broadway revival, which started previews on Tuesday at the St. James Theatre in New York City. The show is set to officially open on November 16.

The Thank You Next singer was decked out in medieval robes, white mesh gloves, and a paper Spamalot crown for the occasion, while an accompanying friend dressed up as a knight of the Round Table.

Ariana carried the show's Playbill as she made the walk from the theater to her awaiting limousine afterward. Fans mobbed the star along the way, begging for pictures.

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Ethan and Ari were first linked back in July, as they both filed for their respective divorces.

Since then, the two have mostly managed to stay out of the public eye but are heavily rumored to be living together in New York City, as the ongoing SAG-AFTRA strike is preventing the final filming days of the much-anticipated Wicked movie musical.

Ariana's divorce from her ex husband Dalton Gomez was officially finalized on October 6.