You've got me wondering if Connecting the Dots is a real book; it sounds that way! And Draco does make a most unlikely old friend, yet it is not inconceivable.
This is a sweet conceit, if slightly OC for SS and HP. It has a great ring of authenticity to it that makes me wonder if you've been through this with someone. I really admire the way you work the necessary information about their bonded state and near-simultaneous ending into the casual conversations of the characters, and, well, just because no one thinks old people can feel romantic, I applaud you.