Though she deeply admired Grant and felt drawn to him, she remained emotionally bound to Carlo Ponti, who had been her mentor and guardian since she was 16. Loren later said she felt that leaving Ponti would be a betrayal of loyalty, despite her strong feelings for Grant. Their romance continued during and after filming, particularly while they were shooting Houseboat (1958) — another film that originally stemmed from their relationship. The screenplay was reportedly rewritten by Grant himself to feature Loren as his love interest.
But by the time Houseboat was made, the relationship had already cooled. Carlo Ponti had managed to legally separate from his wife and was making plans to marry Loren. The tension between Loren’s personal loyalty and Grant’s deep affection became unbearable. Grant, heartbroken, ultimately stepped back. Loren later described their parting as “devastating,” saying that Grant had represented a kind of love that was both passionate and impossible.