Children of Dune - Frank Herbert

"Indeed," Leto said. He lifted himself from the throne, a curiously fluid motion as though he kept his terrible powers under most delicate control. Leto stepped down then to Ghanima's level, moved her gently until she faced away from him, turned and placed his back against hers. "Note this, cousin Harq al-Ada. This is the way it will always be with us. We'll stand thus when we are married. Back to back, each looking outward from the other to protect the one thing which we have always been." He turned, looked mockingly at Farad'n, lowered his voice: "Remember that, cousin, when you're face to face with my Ghanima. Remember that when you whisper of love and soft things, when you are most tempted by the habits of my peace and my contentment. Your back will remain exposed."

Turning from them, he strode down the steps into the waiting courtiers, picked them up in his wake like satellites, and left the hall.

Ghanima once more took Farad'n's hand, but her gaze looked beyond the far end of the hall long after Leto had left it. "One of us had to accept the agony," she said, "and he was always the stronger."