When Applejack starts dating an old pegasus friend, she thought the worst part would be making time in her busy schedule for romance. She didn't expect a whole truckload of unusual complications.
Complications like splinters. A hostile home environment. Being confused for an egg. A book that contains the secrets of the universe, and a theory about a rubber band.
Some ponies just have to worry about their jobs and who did the laundry. Applejack has to worry about her species tearing her love life apart. Pegasi are weirder than she thought, and the universe isn't making it any easier.
Preread/proofread/nonsense-checked by Tchernobog and Timaeus.