Lightning Dust & Twilight Sparkle: After Lightning Dust gets kicked out of the Wonderbolts Academy, Twilight gets the story from Rainbow Dash about what happened in the academy involving her. She finds Lightning Dust packing her things, and to her surprise, doesn’t flat out scold her. Instead, she just gives her a moderate lecture, which opens her eyes a fair bit.
 
Realizing that she could have had a pony like her at one point in her life, Dust makes a vow to meet up with her again.
 
Years pass after Twilight becomes a Princess, she requests that she meet with Lightning Dust again. They do find her, and Twi learns that Dust had been taking her lesson to heart. With that affirmation, Twilight soon gives her the position of a royal guard.
 
Lightning gradually shows feelings towards Twilight in the smallest of ways; complimenting her mane, fetching her a certain book she needed, etc. Well, Twilight surprisingly found that she started to feel a small crush towards Lightning and soon asked if they could possibly have dinner one night.
 
The two were dating in secret until Cadence finally asked about Twilight’s ‘little guard friend’ thus embarrassingly confessing the relationship between the two.
 
And months later, after Lightning comes back from a dispute between the ponies and Diamond Dogs, Lightning asks for Twilight’s hoof in marriage and excitedly accepts the proposal.