Mark Ruffalo Had No Clue Brie Larson Was in ’13 Going On 30′ With Him — See His Priceless Reaction!

Oops! Mark Ruffalo has had quite the Hollywood career and has crossed paths with many stars, but even he didn’t know that Brie Larson was in 13 Going On 30 with him — and his reaction is priceless.

“Oh, my God. That’s amazing. Wow, I didn’t know that,” the 51-year-old said after being told by Entertainment Tonight that Brie, 29, was in the 2004 hit he starred in alongside Jennifer Garner. “We didn’t work together [on that movie],” the actor clarified, taking a look at a still from the film.

Both actors have gone on to receive plenty of attention for their acting. For instance, Brie won an Oscar for 2015’s Room. The pair are now part of the Marvel Universe, as Mark plays the Incredible Hulk, while the Short Term 12 actress is Captain Marvel in the film of the same name.

The Avengers actor recently told the outlet just how much he enjoyed spending time with Jennifer while filming the popular movie back in the early 2000s. “We had the sweetest time. She was a big star then but I was kind of just starting out. She was just so lovely,” he recalled. “We were making this really sweet movie that had a great message for young girls. We were all sort of coming into our own in that moment. We really loved that story and Jen was just transformed into a 13-year-old girl. It was really amazing.”

13 Going On 30 is celebrating its 15-years anniversary and, while it continues to have fans all around the world, don’t expect a sequel — this coming from the movie’s star herself! “What, like 15 going on 50?” Jennifer, 47, joked on a Good Morning America on April 12. “Let’s simmer down. Leave well enough alone.”

Here’s hoping you own the original on DVD so you can watch it on a loop. See if you can spot Brie’s cameo!