whew!!! it’s been a while since I animated myself to the point of physical pain!!!
"I had told Frank—Leave me. But he could not." Claire thinks awfully highly of Frank. He didn't leave but he also dictated every term of his staying, & got a child in the process. And had side women to get what C couldn't give. He gained nothing by leaving but gained a lot by staying. Having wife and child was a requisite for any professional man in the 40s/ 50s. To me, his staying wasn't altruistic or indicative of some great love for C. It was calculated to help himself, maybe tangentially C.