They die first, at around 30 years old. You live for several decades after they die.
You die first, at around 30 years old. They live out the rest of their life without you.
They end up being two faced. You separate after their betrayal and never speak again.
You die alone and content, without ever having loved too deeply (the scenario in the question never happened).
You love and date several people, maybe even marry, but are never really are content. (The scenario in the question never happened).