Bruce Banner: Natasha, where can I go? Where in the world am I not a threat?
Natasha Romanoff: You're not a threat to me.
Bruce Banner: Are you sure? Even if I didn't just... There's no future with me. I can't ever... I can't have this. Kids. Do the math. I physically can't.
Natasha Romanoff: Neither can I. In the Red Room where I was trained... where I was raised, they have a graduation ceremony. They sterilize you. It's efficient. One less thing to worry about. The one thing that might matter more than a mission. Makes everything easier. Even killing. You still think you're the only monster on the team?