He felt, rather than heard Ron and Hermione approaching from behind. These days it was nearly impossible for someone to sneak up on Harry, so he turned around to face his two best friends. Both looked startled at him, likely sensing the accidental outpouring of his magic and seeing its effects first hand. Seeing their unease, Harry pulled back on his emotions to rein them in. These were his friends- getting angry at them wouldn’t do anything but make him feel even worse.