My interpretation: Twilight's duties to the State, and her own complete obsession to her duty and her own personal flaws ended up with her neglecting Spike; and at one point they both only communicated through letters and eventually, not at all. Spike; already feeling like a outsider as he's... Well, a Male Dragon in a Matriarchal society of magical talking Ponies, decided to pack his bags, said farewell to his old friends, and began to wander the world and Twilight didn't even notice.



Twilight eventually fell in love and gave birth to a son, who turned out to be a rather spoiled brat. And Spike... Was actually a pretty decent guy. He has been everywhere from the frozen Lands of the Penguins glorious city of Talon, the Capital of the Griffins. He has been at various points; a Whaler, a Writer, and even a Houscarl for the Jarl of the Bears as well as having many other careers, some being more successful than others.



However; one day Twilights spoiled, bratty, and cruel son, who was being groomed to be the new element of Magic, crossed paths with a young Zebra Spike was raising as a Apprentice. Twilight's son attempted to force himself upon the Zebra, but Spike stopped him and killed him in a fit of rage. Twilight appeared and... Well...



"You promised you wouldn't kill anypony!"

"And you promised you wouldn't leave me!"