The actress opened up about her split with Penn for the April issue of WSJ magazine.
"There is a need to sensationalize things. When you leave a relationship there has to be some ... Crazy story or some crazy drama. And the ... Ghosting thing, like literally, I still don't even know what it is. It's just its own beast," she said.
"We were in a relationship and then it didn't work anymore. And we both decided to separate. That's it."
"We were very, very new in a relationship. The stories that Sean was going to adopt Jackson, and all of that was not true. It's not something that happens in 18 months. You can't do that to a child," she said.
Also Read
Theron, however, credited Penn for being careful and understanding about her adopted son.
"There was an understanding that I was a single mom with a very young boy who I had to put in a situation where he understood that Mommy dates, but that he does not have a father, you know what I mean?.
The actress, 40, said she felt responsible and adopted her second child August as a single mother even though they were in a relationship.
"And in my honesty about wanting to have more kids, there was an understanding that a relationship had to go somewhere before it was going to be-what you hope for, which ultimately did not happen.
"I couldn't foresee that, but that stuff takes time and I think it's my responsibility as a mother to protect my child from that. And we had a very clear understanding. He knew that I was thinking about filing for another adoption, but that we weren't filing together.