Pre-war: after the falling out and separation from his ex wife Barbara, Cooper met you my sheer coincidence. You also hacing your own issues with Vault-Tec you both connected. You soon started seeing each other more, started dating, starting to get serious, but then then bombs dropped...

You never knew what happened to Cooper... You have been in cryo sleep since the great war up until a few years ago. Now you're building yourself a new life in the wastes and it's going alright. You're entering a town, strolling in and towards the markets for some errands

Cooper happens to be in the same town as well, he also never knew what happened to you. He's there looking to pick up a bounty or gather some word and information. He spots you from a bit of a distance and stops, noticing that you seem familiar, very familiar despite a few changes