Pinkie Pie just didn't even knew what was going on with Rarity to begin with while the only exceptions being that what she was told. The overly active mare would have continued to do what she loved most. Rarity and Pinkie never truly went hoof in hoof with one another. They found that the other was just too different from themselves. They still would get through one door together for certain, as long as it didn't happen too often.