Madeleine deliberately emphasized the words "brother and sister" because she wanted Howard Coleman to know that what she was doing was the same as him, merely bearing in mind the affection of growing up together from childhood, and nothing more.
It was truly sad. She had never imagined that her love for him would one day reach the point where she had to desperately make him feel that she didn't love him.
Madeleine lowered her head, blinked her eyes, then turned away, continuing to face away from Howard.
All she had to do was lift her eyes, just lift her eyes, and she could see that the moment Howard heard the words "brother and sister" from her mouth, his face instantly turned pale.
Howard stared at the back of Madeleine's head that she left him to view, pursed his lips, and after a long while, turned his head to gaze directly at the road ahead.