Mark Ruffalo had no idea he starred with Brie Larson in '13 Going On 30'.

The 51-year-old actor stars as Bruce Banner - who transforms into The Hulk - alongside Brie, 29, as Carol Danvers aka Captain Marvel in Marvel Cinematic Universe ensemble blockbuster 'Avengers: Endgame'.

Mark thought it was the first time he worked with Brie as he didn't realise that she'd had a small role as one of the mean girl gang the 'Six Chicks' in the 2004 film - which celebrated its 15th anniversary on Tuesday (23.04.19).

When shown a picture of Brie in the film by ET Online, he said: ''She was a mean girl! Oh my god, that's amazing. I didn't know that. It looks a lot like her. It is her! How cool, I didn't know that. Did she talk about that?''

The interviewer mentioned that being on the film's set inspired Brie to become a director to which he responded: ''Gary Winick directed that, rest in peace Gary. That was a lovely little movie.''

Brie previously admitted she can vividly remember how fascinated she became by the filmmaking process because of her stint on '13 Going On 30'.

The Hollywood beauty - who helmed 2017 fantasy comedy film 'Unicorn Store', in which she also starred - said: ''I was [in '13 Going On 30']. I remember it was like the moment when I realised that I really wanted to direct. I remember paying a lot of attention to where the camera was and the camera moves, thinking about how I would have cut it together and then seeing the movie and seeing how it differed from what I thought.''