i had two vague ideas in mind and i'm down for brainstorming specifics for both but! one would be something that was one of those on-and-off intense kind of situations where they fell too hard too fast - it didn't last very long but it was an instant connection, and the other would be something a lot more serious - they both assumed that they'd found 'the one', they were together for a year or two and assumed they were building a life and a future together, but something happened and it all fell apart. or a mixture of both somehow! like i said, totally open to hashing out the details