Grey's anatomy 5 10

Episode 10: "Holidaze"

Mark: It's the guilt, you know? It's like every time I look at her... I just... The guilt is like a punch in the gut. Everyday.
Derek: Well, you shouldn't feel guilty, you didn't know.
Mark: I did know. I knew it when her mom got pregnant. She told me. I gave her a couple hundred bucks and I left town and I never saw her again. I figured she got an abortion. Hoped. But I did know.
Derek: Well you're a different guy now. You're not 18 anymore, you've grown up, and you're capable of better. 

Miranda: So, how was the view?
William: I have been a proud father. Your whole life, I have been a proud father. Your mother and I sat in the front row of every dance class, every oboe recital, and we cheered. We sat in the front row of every graduation, I was always the first one on my feet, and the loudest one in the crowd. I have been a proud father. And today, Miranda, I sat in the gallery, and I watched you repair some fat man's hernia. And for the first time in my life, I felt ashamed of you. This is what you do on Christmas? For this you traded your husband? For this, you traded your child's family? So you can work all day, and go home alone, on Christmas, to an empty house, without even a tree. I have been a proud father, Miranda, but I would be a bad father today if I didn't look you in the eye and tell you that you have made a terrible mistake. You broke your family, you set your son up to fail. And the child that I raised, she was raised better than that.