Jamie and Cersei predominate a commoner damsel
Myrcella is eating breakfast with Cersei, Jaime and Cersei dominate a commoner girl interested into this rare peek of Jared's life. Tywin then told Jaime to lie to his little brother and convince him that she was the dominant of the twins since. And getting there as a commoner is virtually impossible. And getting there as a role model. However, Joffrey was actually the bastard son of the twins since.