Keira Knightley's former lover Jamie Dornan has cashed in on their romance by writing a song about the British actress. The Irish model enjoyed a two-year romance with the PRIDE + PREJUDICE beauty, but bailed when her escalating fame put pressure on the relationship. He says, "The song hurts so much when I sing it. I'm in so much pain afterwards. "It's about the difficult times in a relationship, everyone has them - I still speak to Keira, we were so in love." Of his failed relationship with Knightley he says, "I was intimidated by certain things that came with her fame and I began to feel out of my depth. "It's still hard to talk about."