After Discord is reformed he starts spending time with Princess Celestia and Celestia develops strong feelings for him. Discord, not knowing how to react, gets mad. Celestia feels like it was her fault and becomes depressed. Discord realizes that he over reacted and wants to show her that he feels wrong but he doesn't know how. Cadence thinks she can help and without really trying she ends up getting them to fall in love. Celestia and Discord keep their love a secret knowing that if anypony knew they would be separated.