Arnold Schwarzenegger

AP

Arnold Schwarzenegger is confirming that he had a "hot affair" with actress Brigitte Nielsen at a time he and Maria Shriver were dating and already living together.

Schwarzenegger and Nielsen co-starred in the 1985 film "Red Sonja." Nielsen write in a memoir published last year that she and Schwarzenegger had an "outrageous affair" while making the movie and that she did know until later that he was involved with Shriver, reports The Associated Press.

In his memoir "Total Recall," coming out Monday, Schwarzenegger writes that he and Nielsen did indeed have a "hot affair," but he knew it wouldn't last. In fact, their "fling" only made him realize that he wanted to marry Shriver.

Nielsen would soon marry Schwarzenegger's fellow action star, Sylvester Stallone.