Katy was enjoying the water slides when…

Her bikini bottoms slipped off! Of course, because Katy’s such a big star, there were cameras on hand to capture her embarrassing moment.

How did Katy react? She just laughed it off! These things happen to everyone, so it was a good move on her part not to take it too seriously.

Here’s what she posted on Twitter:

“To be fair, I really think I deserve a season pass for that ass. Oh, and some flip flops.”

Sources: Huffington Post and @KatyPerry