Radcliffe and Darke met on the set of a film like many actors do. The pair starred in the 2013 film "Kill Your Darlings," in which Radcliffe portrays American poet and author Allen Ginsberg. Though Darke doesn't have a large role in the film as Gwendolyn, her on-screen presence was impactful enough to gain the attention of Radcliffe.
Not long after the two met, Radcliffe and Darke started dating. Touching on their relationship, the "Harry Potter" actor told Parade in August 2014, "We met on the set of 'Kill Your Darlings,' and just got on immediately. It was one of those instant things where you're like, 'Oh, I really like this person.' You just have a connection with somebody, and then suddenly it's incredibly easy to talk to them. It was one of those sort of situations."