Letterman begins the conversation by stating how marriage changes one's purpose in life to not being about themselves. "I have to say, before I had the twins I felt that about her," Clooney says in the clip released ahead of the episode's Friday premiere.
"I felt that I met someone who I would absolutely trade my life for. I met someone that her life meant more to me than my life, and I'd never had that experience before," the actor continues.
Letterman's talk with Clooney comes after the 70-year-old interviewed Barack Obama where the former president shared a story of how is daughter Sasha asked him to dance while late musician Prince was performing.