For Dora, it was the first relationship; it was the best relationship. For Dora, it was built on trust and friendship, and also on respect and love. For Dora, it seemed as though nothing could be more perfect than knowing that she belonged to Remus and Remus belonged to her.
For Remus, it was a ticking clock. It was the thing he would spend his life doing until his life ran out. It was never pretending to love her, but always pretending he loved her the most. It was guilt; it was lies. For Remus, it was knowing that no matter how much she loved him, no matter how much he adored her, it would never be what he had felt for Sirius. And that was simply what it was.