They seem'd, to those who saw them meet,
The casual friends of every day;
Her smile was undisturb'd and sweet,
His courtesy was free and gay.

But yet if one the other's name
In some unguarded moment heard,
The heart you thought so calm and tame
Would struggle like a captured bird

And letters of mere formal phrase
Were blister'd with repeated tears,
And this was not the work of days,
But had gone on for years and years!

Alas, that love was not too strong
For maiden shame and manly pride!
Alas, that they delay'd so long
The goal of mutual bliss beside!

Yet what no chance could then reveal,
And neither would be first to own,
Let fate and courage now conceal,
When truth could bring remorse alone.

Richard Monckton Milnes Houghton

http://www.poemhunter.com/poem/shadows-159/