Hermione remembers the exact moment that Ron Weasley died. His final expression never fades from her / Draco accidentally killed Pansy Parkinson when he revealed his alliance with the Order. Her final words still haunt him. In the kitchen of the safe house, nothing matters. No one else is around to see them belittle each other anymore. They know they are both messed up

"I should not want her." Draco quivered. "Because of who she is?" His mother asked, hopeful he would say yes. "Because of who she will be..." A single tear ran down his cheek and curved down to lip. Narcissa wiped it away with her finger, pulling his face down to meet her forehead. "A Weasley."