Credit: Broadimage

Earlier this week, Heidi Montag began shooting her first-ever film cameo in the 2011 romantic comedy Just Go With It, starring Jennifer Aniston and Adam Sandler.

And reality star-turned-singer, 23, still can't get over the experience.

"I just had THE BEST day of my life filming my first comedy movie!!!!!" she Twittered Monday. "It was beyond what I could have ever dreamed!!!!!"

What's more, she wrote, "I am wearing my sailor shorts I designed in the movie!!!"

After she wrapped up her second day of shooting, Montag Twittered that she was more in awe of Hollywood than ever. "I LOVE Adam Sandler!!" she wrote.

As for Jennifer Aniston, the star admitted on Monday that she had "just heard" about Montag's cameo in the film. "That's interesting and fun," Aniston, 41, told Access Hollywood. She added that Montag is "perfect" for the part.

Montag recently replaced husband Spencer Pratt as a manager with Aiden Chase, a Malibu-based psychic.

"Heidi's dreams are big," Chase tells "She believes them, and I believe them."