After working together to save Equestria, Rainbow Dash and Flash Magnus ended up becoming really good friends. So close in fact, that Dash was curious about taking things further. However, Flash seemed to be resistant for an odd, but big reason...
Call me Troubleshoes. You're probably darned curious to know how a stallion like me ended up scoring with the Spirit of Chaos. Frankly, I ain't so sure either. But I'll explain it as best I can.
Twilight Sparkle arrives in Ponyville to prepare for the Summer Sun Celebration, and potentially the return of Nightmare Moon. All that stands in her way is five stallions who keep flirting with her. Making passes. Hitting on. You get the idea.
After being banished, Nightmare Moon finds she is able to talk with Discord, also sealed away. The two despise one another, but talking with a hated foe is better than endless monotony. Over time, the two fall in love, up until tragedy strikes.