The actor, who is married to the former Gossip Girl star, has played the foul-mouthed Marvel character in two standalone films, with a third on the way.
Reynolds has won acclaim for the role, and even received a writing credit for Deadpool 2, which was released in 2018.
However, in a new interview, Reynolds has attributed the screenplay’s greatest contributions to Lively.
“She’s helped me so much in Deadpool – all kinds of movies that have been big successes,” he said on recent SiriusXM Town Hall with Jess Cagle (via PEOPLE).
Reynolds, who called his wife “a really talented, multi-hyphenate kind of person”, continued: “There’s a lot of A-plus plus writing that I’ve done that was actually Blake. Blake would jump in, grab the keyboard and [say] ‘What about this?’ And I’d be like, ‘That’s incredible.’”
The actor said that, while he told his director David Leitch and the film’s producers about Lively’s contributions, it was only Reynolds that received the co-writing credit alongside Rhett Reese and Paul Wernick.
He also stated that producers seemingly ignored the fact that Reynolds told them Lively helped him after the film was released.
“Maybe it’s ‘cause there’s inherent sexism in the business,” he said, stating: “I will say that a lot of times – ‘She wrote that. Blake wrote that; not me. That was her.’ And it’s like, they still, later on, repeat the story as ‘I wrote it.’”
Access unlimited streaming of movies and TV shows with Amazon Prime Video Sign up now for a 30-day free trialSign up
Reynolds, who stars in new film Free Guy alongside Killing Eve star Jodie Comer, said he is “70 per cent” sure a third Deadpool film will begin shooting in 2022.
The Independent has contacted Lively for comment.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies