The light and pure joy in Buck's eyes when he looks at Tommy. The light and joy that most definitely was not there with any of his previous girlfriends.
Caeso- you have our entire lives and souls in your hands, our good man. We wish you all the happiness this world can offer, and We want you to know you are doing wonderful! Have no doubts. If your predecessors were present, they would not be angered, but be delighted at the chance to have another brother.
Such determination to continue on despite the world deeming you should not is something we admire greatly. Don't lose that.