In Deathly Hallows – Part 2 when George sees that Harry is alive and immediately turns around to tell Fred — only to realise that his twin will never stand by his side again.
When Harry, Ron, and Hermione are forced out of No. 12 Grimmauld Place by Death Eaters and realise that Kreacher, who finally has a life purpose and enjoys their company, will have no idea why they've abandoned him.