But Theron now says it was not true.
“No, we went out, that was literally all we did, we went out,” Theron said.
CNN has reached out to Penn representatives for comment.
The couple were reportedly an item until they separated in 2015.
“It was a relationship, to be sure. We were definitely exclusive, but it was for just a year,” Theron told Stern. “We never moved. I was never going to marry him. It was nothing like that.”
It is not the first time that Theron has tried to make things clear about his relationship with Penn.
“We were in a relationship and then it didn’t work anymore,” Theron said at the time. “And we both decided to separate. That’s all.”