The 20-year-old star of the film and 37-year-old author of the book were also joined by leading lady Cara Delevingne.
During the Q&A, Nat opened up about why he wanted the role.
“So I was on set of The Fault in Our Stars and somebody came up to me and said you should really read “Paper Towns”…I read [it] and it was my favorite by far of John‘s books,” Nat told the audience, joking, “The rest were so lame. By such a huge margin.” Watch below!
FYI: Nat is wearing a Dolce & Gabanna suit.
Nat Wolff & John Green at Paper Towns London Fan Event