The Oscar winner also revealed that her son isn't aware yet that she's an actress: ' I just go to work'
“Louis has no idea what an Oscar is, he’s not seen it, doesn’t know what it is, and Louis has no idea that I’m in this film,” she added.
The Oscar winner, 50, voices supervillain Scarlett Overkill in the movie spin-off of Despicable Me.
Bullock, who dazzled in a Stella McCartney silver brocade dress, said she chose to make the movie for Louis, whom she adopted in 2010.
“I wanted to make something my son could see and watch and enjoy, even though he doesn’t know what I do and he doesn’t know it’s me – I can sit in the theater and watch him,” she told the Belfast Telegraph, adding, “Nothing makes me happier than hearing that boy laugh, [by] physical humor and animation so hopefully I’ll be able to do that.”
The star also spoke out about being named PEOPLE’s 2015 World’s Most Beautiful.
“I know, shocking isn’t it,” she joked to Access Hollywood.
Bullock called her PEOPLE cover the “beautiful-on-the-inside-issue,” saying, “The outside can still be what it is, it’s what you got.”