Sometimes repetition works - tell them you love them every day.

Triolets, short love-notes with an echo

Sam and Rosie

This memory I shall hold dear,
My Rosie, ribbons in her hair -
For even through the pain and fear,
This memory I shall hold dear:
Her laugh alone I'd sometimes hear...
I saw her at the party fair.
This memory I shall hold dear,
My Rosie, ribbons in her hair.

( Tom and Goldberry )
( Elrond and Celebrian )
( Eowyn and Faramir )
And one that isn't exactly romance, but certainly faithful friendship:
( Sam and Bill the Pony )