For a long time, Flash Sentry of Equestria had a colthood crush on Princess Celestia’s personal protg. She was hot-tempered, and not all that humble, but young Flash sensed something that she desperately needed; a friend. He had always wanted to be that friend, but alas, she disappeared one day, and was never heard of since. Until Celestia’s other student became princess. He was delighted, and ashamed to hear what Sunset had done, and for a time after Princess Twilight returned, he had went out with her, feeling some other worldly connection. That connection, however didn’t last, and his heart still felt tied to his colthood crush.
 
He decided to talk about it with Twilight, being honest and telling her about the mare he truly loved. Moved by his words, and also feeling a loss of connection with this version of her love, decided to write to Sunset Shimmer with a great idea.
 

 
At Canterlot High, Flash Sentry only had one person on his mind; Twilight Sparkle.  
He couldn’t deny it, he was in love with a pony from another dimension. He rarely talked about his feelings, and when he did, it was either to his closest friends, since they understood the mad concept, or to Twilight’s friends.
 
One day at a band-jam in the music room, Sunset’s backpack started to hum, and vibrate. The band stopped as the old student to the Sun Princess opened her bag, and her book, and began to read what the Princess of Friendship wrote.
 
 
“Dear, Sunset Shimmer,
 
Hi, how is everypo-everybody? Good, I hope, anyway, I have an idea.  
I’ve been seeing the Flash Sentry of our world, and we aren’t happy, and here’s why; He’s in love with you, Sunset. I know it sounds crazy, but he’s been an admirer of yours since you were Celestia’s student. I think you two would get along well, and if I can be honest…..I miss my Flash.
 
So, here’s what I’m thinking. Tomorrow, or whatever time it is….anyway, you let my Flash know about this, and then write me back. I’ll open the portal, and send your Flash though the portal. We’ll do a switch so the dimensions will stay in balance.  
I hope this is okay with you, and you’ll have to help him adjust to waking on two legs, and eating…..anyway, just let me know what you think, and when you’re ready.