Meghan Markle's wedding dress gets criticized by Katy Perry

Katy Perry’s going to tell it like it is!

The 33-year-old pop star opened up to ET’s Lauren Zima about this weekend’s biggest event – the Royal Wedding of Prince Harry and Meghan Markle – during Sunday’s night one of the "American Idol" finale.

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“I would have done one more fitting,” Perry quipped of Markle’s stunning Givenchy gown. “I’m never not going to tell the truth! One more fitting, but I love you.”

First kiss #RoyalWedding

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She added that she preferred Kate Middleton’s 2011 Alexander McQueen bridal look, adding, “Kate, Kate, Kate won, Kate won!”

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Despite her slight criticism of Markle’s dress, Perry added, “I’m so happy for them, and, you know, I don’t know them from Adam, but it’s amazing what she’s doing with all this, her humanitarian efforts. You know, the fact that she’s a proud feminist, I love all that, so I support her as another woman and love her and wish them both well.”

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Perry’s fellow Idol judge, Lionel Richie, also gave some insight into what this wedding meant to him.

“I remember when Di had them, Lady Di, and it was amazing and now to see them both married and kids, well not yet, but married,” Richie, 68, told ET. “She would be very proud. I must tell you, I mean, it’s a moment in time, but I’m glad to see they’re moving on as young men now, as family men. I love that.”

The finale of American Idol airs Monday on ABC at 8 p.m. ET.