Sunset and Rarity's relationship was always thought to be platonic, they thought that too until Sunset gets attacked and they realize that their relationship may not be as platonic as they originally thought.
When Sunset is redeemed, she starts to feel obligated to help out others. She tries to work out the confusion in both her heart and mind through selfless acts. This causes a certain new friend to notice her in a different light...
How do you choose a gift for someone who has better taste than you do? If you're clever, you find a way to ask them that means they'll never find out you cheated.
Sunset and Twilight are dating. They know Rarity has feelings for Sunset. They've asked her out to dinner together. Rarity is not panicking. It's far worse than that.