The Oscar nominee publicly shared the news while appearing alongside the WWE star on the July 21 episode of Jimmy Kimmel Live. When guest host Anthony Anderson mentioned there's a "backstory" between The Suicide Squad castmates, the actress made a surprising confession.
"I watched WWE when I was growing up, when I was a kid I loved The Undertaker," Robbie explained. "And then obviously when I was a teenager I stopped watching. But then, as a late teen, early 20s, I had a boyfriend who was obsessed with John Cena. So much so that he dressed as John Cena for his 21st birthday and had a cardboard cut-out in his bedroom."
"So I slept in a room for two years with a life-size cardboard cut-out of John Cena in the room," she laughed, noting that sometimes it would startle her when she'd wake up in the middle of the night. "And then I'd be like, 'Oh, it's just John Cena, it's OK.'"
Robbie, 31, then recalled questioning whether or not to tell Cena, 44, about this life-size object before they started working together. While initially deciding to keep it to herself to avoid any weirdness, the Focus star ended up spilling the secret "five seconds into meeting him."
After Robbie shared the revelation, Cena was then presented with a life-size cardboard cut-out of her The Suicide Squad character Harley Quinn. "You also have to sleep with that in your room for two years," Robbie told him, "just to level the playing field."
His response? "OK."
Take a look at the interview above to see Robbie share her hilarious story.
The Suicide Squad is set for release on August 6.