When Rey came home from the academy - as a top graduate, too - Gilbert couldn't have been more proud. Dressed in a red ZAFT uniform, Rey looked like a young man.
When he realized things were different and asked, "Where's Rau?", Gilbert was at a loss for words. Rey's face fell and his eyes began to search desperately. He looked like a lost child.
Gilbert carefully reached an arm around the blonde boy's shoulder and pulled him close. Forcing himself to smile for Rey, he said, "Do you remember when I told you, 'others are what you can never replace'?"