Shortly after Flurry Heart’s birth, Cadence was revealed to have been cheating on Shining with various stallions. It also turns out that Shining was doing the same. Their marriage was clearly sour, but they decided it was for the good of the Crystal empire to stay together.
That was, until Flurry Heart disappeared at the age of about 2. The couple couldn’t take it and divorced on horrible terms. The only thing they agreed upon was that they’d never see eachother again.
Years later, these two were born. They grew up not knowing of eachother or their parents’ secret pasts. The two met and immediately fell in love. However, they had to keep it a secret in fear of it being considered scandalous.
Now they know that their parents knew eachother, and are on a mission to find out how exactly they knew eachother and what happened to Flurry Heart.