Neither Starlight nor Sunburst have visited their parents in a long time, but when both are called by the map to their hometown, they discover their parents are at the center of the friendship problem.
My Little Pony: Friendship is Magic Season 8 Episodes...
"Get your muzzle out of those books and make some friends!" That's what Princess Celestia tells Twilight Sparkle. She may be the smartest unicorn in Equestria, but Twilight Sparkle gets an "incomplete" in friendship. There's more to life than learning magic, after all - so she goes to Ponyville on a mission to make friends. There she meets five special ponies who take her on exciting adventures and teach her the most powerful magic of all... the magic of friendship!
My Little Pony: Friendship is Magic - The Parent Map Synopsis and Schedule