“Grandmommy, are you sure I REALLY have to wear this dress?”
 
“Why not, Nebulosa? You look pretty in this dress! I bet you’ll grow to be a beautiful mare like your mother”
 
“Ummm…suuuure. laughs nervously, then thinks ‘I don’t like dresses…I don’t like living like a filly’”
 

 
Before he came out as trans, Spheranium was known as Nebulosa Spheranium Sparkle, the second born daughter of King Thorax and Queen Twilight Sparkle. When he was a colt, he didn’t know how genders work but he knew perfectly he wasn’t like all those fillies, in fact, he didn’t even feel like one. He wanted to play with other colts and act like them, but they always rejected him because he was a “stupid filly and a pampered princess”.
 
It took him about five years to get deconstructed about gender identity and he finally realized he wasn’t weird or confused, but a young stallion born in the wrong body. He told his parents about his feelings and they took it incredibly better than he expected; however, Night Light and Twilight Velvet don’t seem to understand his situation and instead they believe he’s just “a butch young mare who likes mares too much she wants to be a stallion” (don’t worry, they’ll grow out of it and call him by his correct pronouns eventually).
 
Now that he’s older, he knows that wearing dresses or long hair isn’t only meant to be done by mares, but he still doesn’t like them. He still wears his mane long, and doesn’t mind helping his sister to choose a dress from Rarity’s collections. Most ponies in Equestria have accepted his pronouns and respect that they don’t have two princesses, but a princess and a prince. However, a Gryphon pony named Gaston seems to be a headache for the karkadann prince, calling him a confused pony. But Spheranium knows he doesn’t need to prove anything, as long as he feels happy with himself.
 
Also, if there’s something I missed or portrayed wrong let me know! I wrote this story out of things I’ve investigated, along with stories from a few trans Youtubers I follow and I don’t mean to offend anyone.