The three take in Alice in Wonderland while William travels Down Under
Credit: Jackson Lee/Splash News Online; inset: BEImages

They were three on the town Tuesday: Kate Middleton spent the night at the ballet with her soon-to-be in-laws, Prince Charles and Camilla.

As her fiancé Prince William was on the other side of the world tending to official business and showing U.K. support for the disaster areas of New Zealand and Australia, Kate, 29, was kept company in the grandest of surroundings.

She was taken to London’s Royal Opera House in Covent Garden to take in the final performance of the Royal Ballet’s brand new, full-length Alice’s Adventures in Wonderland. There, in the royal box, she was seen sitting between Charles, 62, and his wife Camilla, the Duchess of Cornwall, 63.

The outing marks the second time in as many months that Kate was seen with Camilla. The last time was when the two had lunch together at Koffmann’s restaurant at London’s Berkeley Hotel.

Surprisingly, the V.I.P. trio went largely unnoticed during the performance Tuesday.

“It was only when the cast, which is vast, turned to their left to curtsy to them, that most of us realized she was there,” an excited ballet fan tells PEOPLE. “Kate was smiling broadly as she joined in the applause.”