"Flash! Flash!"
Twilight came running to the dark-blue-and-light-blue maned stallion wearing the Royal Guard armor.
"Hey, Twi! Congratulations to being a Princess now..." Flash Sentry brohoofed her.
They were at the back of the Canterlot Castle, the ground filled with old, dried-up leaves from old gnarled trees, and pieces of plastic were scattered all over the place. A good place to be a Secret Hideout.
"Thanks!" Twilight Sparkle giggled. "How did you even, you know, became a Royal Guard? I mean, it's been a while since we met in Magic Kindergarten, and then we met again after I journeyed to Canterlot High." She shivered at the memory of fingers and legs.
"Well, my father is one of the Royal Guard, and so he brought me here to train to be one. I missed you so much those days we were apart. All of the ponies in Middle School are Sunset Shimmer clones. Ugghh." The Guard shivered.
"But it's a good thing that we met again, thank Celestia." Twilight poked Flash.
The two of them poked each other until it was time to say goodbye.
"Bye, Princess!" Flash waved.
"Goodnight, Flash!" Twilight waved back.

Author's Note

I don't really know if Flash's father is one of the Royal Guard back in the days of our fathers. I just used it because I thought that that* was the reason on why Flash is one of the Royal Guard, so don't think that it is the truth.

*Try saying it. that that. I did it in purpose.