The last line echoes the exact same thing Jaime said right before he pushed Bran Stark out of a window in the pilot episode of "Game of Thrones."
Bran caught Jaime and Cersei having incestuous sex in season one. Cersei was frantic when she realized Bran had seen them, and Jaime seemed to believe he had no choice but to silence the 10-year-old boy. Right before shoving him out of the tower window, Jaime turned to Cersei and said "The things I do for love."