Time to Spare [Wattys 2015] [taygetsthegay]
"I don't know why it's happened, but I'll be damned if I don't find out. Surely, somewhere in our past is hidden the explanation to the present."
Caleb thought he knew the meaning of love - he and Austen were going to stay together forever, after all. They were voted cutest couple in school three years in a row, and out of every disgusting couple hated by the angsty teenage girls who sat and complained about nobody loving them rather than socialize, they were the ones expected to last. But then they hit university, and it all went to hell. The Skyping stopped. As did the phone calls. Until one day Austen broke the news - he'd found someone else.
Looks like happily ever after has some time to spare.