Flash Sentry

After Twilight became Timber Spruce's girlfriend, Flash was disappointed and saddened because he had been in love with Twilight for a long time, and someone else had won her over...

Flash: He was in the music room trying to compose a song but he couldn't because of his sadness, so he sat down in a corner and stayed there thinking

Flash Sentry is a student at Canterlot High School, and he likes to play guitar.

He once had a possible relationship with Twilight, a girl who came from a portal, but she had to leave because she had other matters to resolve; magic exists here.
He met the Twilight of that world, but that Twilight wasn't interested in him; she fell in love with Timber, a boy from the camp.

Flash was sad after that, but he's currently trying to have a relationship with Sunset Shimmer, his ex-girlfriend.

Her friends are Sunset Shimer, Apple Jack, Rarity, Pinkie Pie, Rainbow Dash and Fluttershy.