Robert Downey Jr came up with emotional Avengers: Endgame line

Robert Downey Jr. was inspired by his own children for his "I love you 3000" line in 'Avengers: Endgame'.

One of the movie's most touching moments saw his character Tony Stark - AKA Iron Man - telling his daughter Morgan Stark (Lexi Rabe) just how much he cares for her, and it turns out it was a line Downey Jr. came up with himself.

Co-writer Christopher Markus told Fandango: "Well, as much as we'd like to take credit for what is inevitably going to be one of the most memorable lines in MCU history, that is something that Robert and his children actually say to each other.

"He brought it from real life onto the set."

Meanwhile, the Marvel Cinematic Universe directing duo Anthony and Joe Russo have revealed that the spoiler ban has been lifted today (May 6).

Joe explained: "Part of why we make these movies is for conversation."

The brothers had previously asked fans not to spoil any of the movie's major plot points for the highly anticipated movie.

They said: "Everyone involved with the film has worked incredibly hard the past two years maintaining the highest level of secrecy.

"Only a handful of people know the film's true plot. We're asking that when you see Infinity War, in the coming months, that you maintain the same level of secrecy so that all fans can have an equal experience when they watch it for the first time.

"Don't spoil it for others, the same way you wouldn't want it spoiled for you. Good luck and happy viewing. #ThanosDemandsYourSilence (sic)"