Did any first ladies have an affair?

Yes, there have been allegations and rumors regarding affairs involving some first ladies in U.S. history. Notably, Eleanor Roosevelt was rumored to have had an emotional affair with journalist Lorena Hickok, though it was never substantiated. Additionally, more widely known is the affair between President John F. Kennedy and Marilyn Monroe, which raised questions about Jacqueline Kennedy's knowledge of the situation. However, definitive evidence of affairs involving first ladies is often speculative and not conclusively proven.