I know this is 11 & Amy, but this came to mind: "The 10th Doctor: Donna, I’ve been a father before...// Donna: What?..// Doctor: Lost all that long time ago. Along with everything else. When I look at her now I can see them. The hole they left, all the pain that filled it. I just don't think I can face that every day. When they died that part of me died with them. It'll never come back. Not now."