Katy Perry's Wild Wonka Birthday Bash -- More Deets!

Katy Perry celebrated her 25th birthday party with a wild, Wonka themed bash, where guests ate giant lollipops and painted each other with neon paint!

One partygoer tells X17online that Katy set up a "bubble room" for guests like Taylor Swift, Julianne Hough, JoJo and Matt Dallas, to take photos that looked as if they were floating on the bubbles. "Hot young boys" were hired to help paint the guests, although you could dip a hand in a bucket and grab a body and leave your mark as well!

Katy also had a tree decorated with tons of candy for guests to munch on throughout the night.

Boyfriend Russell, who doesn't drink, was very "cool and friendly," says our spy. "Russell's clearly smitten with Katy. But he's not the clingy type, he let the birthday girl work the room on her own, joining back up every now and then to give her a little kiss. They were so cute together!"

Although Katy may have given her guests an intense sugar rush and some ruined clothing, she did give them a very thoughtful parting gift -- A toothbrush and toothpaste to make sure all that candy doesn't cause any cavities!

And although the party continued later (where Lindsay Lohan joined the bash), Russell and Katy went home alone, where they no doubt continued the party on their own!