Once upon a time, a human named Lero Michealides was inexplicably transported to the magical land of Equestria. With no way of returning to his home world, he rolled up his sleeves and fashioned a new life for himself in this world of sapient ponies, adapting to their alien society and way of life, all to the very best of his human abilities.
In time, Lero even managed to find love in the form of a pegasus mare named Rainbow Dash. But this romance would prove to be unlike anything Lero had ever experienced before! He quickly learned that because the pony gender ratio equates to about 5 females to every 1 male, monogamy was NOT embraced by the ponies of Equestria as it was by the humans of Earth. Instead, several females traditionally all married the same male, ("Otherwise, you'd end up with a lot of lonely mares!") unifying in a polygamous 'herd.'
Stunning as this news was, Lero simply did what he did best: he adjusted. He adapted.
He went with the flow.
Soon enough, Lero even came to develop a herd of his own: in addition to Rainbow Dash, there came Princess Celestia's prize student, Twilight Sparkle, and later, the serene martial arts master, Lyra Heartstrings. The four of them were so blissfully, passionately happy together. Destiny had smiled on them all.
But then, one day, Princess Celestia tasked her faithful student with fixing an incomplete spell of a long-dead magical genius.
Twilight cast the great wizard's spell. And in doing so, the Destinies of all her dearest friends were SWITCHED.
Now, while Twilight busies herself finding a cure that'll restore her friends to their former selves, Lero Michealides finds himself in a dire bind, indeed.
One girl, who he never fell in love with -- and who never would have fallen for HIM, in her right mind -- now believes herself to be Lero's soulmate. The other girl -- the TRUE love of Lero's life -- now sees him as a casual acquaintance. And convincing them of the truth is an impossibility.
What will Lero do in a situation where there IS no path of least resistance? Whatever his ultimate decision... hardship and heartache are destined to confront him at every turn.
Welcome, friends, to Divided Rainbow.
[Big credit to AnonAuthor, and all the rest of the Xenoverse canon writers,]