Mr. and Mrs. Cake

Mr. Cake and Mrs. Cake are the owners of Sugarcube Corner. They have an unclear, though definitely close, relationship with Pinkie Pie. In fact, they might be her family (Pie/Cake anyone?). They not only allow her to run the store in their absence, but also refrain from any action, apart from concerned look, when she sabotages their efforts to prepare sweets for Princess Celestia's visit.

They're the only known couple in Friendship is Magic and the ultimate proof that seeming shortage of males in the show does not imply polygamy.

Appearances

 * S1E4: Applebuck Season
 * S1E10: Swarm of the Century