A stallion and a mare discover they can send letters back and forth through time via an unassuming mailbox. Despite being years apart, neither of them is surprised when they begin to fall in love.

But they didn't expect to start fucking.

This story contains light cuckoldry, voyeurism and exhibition, and time travel shenanigans, but absolutely no emotional drama, cutesy feels, or crying. Also sex.

Assisted by tailsopony.