Complex sentence: While looking around at the crime scene, DiNozzo tells Cassidy about his rock-climbing date with Jeanne, and how he couldn't bring himself to tell her "I love you".
Split into simpler sentences: While looking around at the crime scene, Cassidy and DiNozzo make insinuations of a previous relationship. DiNozzo then tells Cassidy about his rock-climbing date with Jeanne, and how he couldn't bring himself to tell her "I love you".