Pet Name
Cas,
It is an abbreviation of this immortal's name;
One he could live without
If everyone but a certain mortal stopped calling him.
Cas,
It is nothing big,
A minor change is all.
But it means something to him,
Something he can't quite grasp.
Cas,
He has never felt this way before,
Not since his Father created him.
It is unexpected,
But not unwelcome;
If only he were to say it.
Cas,
It leaves the mortal's mouth
As if it was a sigh.
It grazes over his lips
And into the immortal's ears
With a confidence and grace.
Cas,
Others say it with a different sort of sigh,
Like that of disappointment and disgrace;
As if those three letters were trouble instead of a grace.
Cas,
His name should be beautiful,
Like that of an Angel born on Thursday.
It should not be a curse,
But a privilege—
If only this immortal's name would grace that
Of a specific mortal
And no others.
Cas,
It is him
Who had given this immortal this name.
It is him
Who had named him so.
It is him
Who should be the only one.
It is him
Who should be the one to have this name grace his lips.
Cas,
This three letter name is but
A joy and a curse;
A joy if it graces his lips,
A curse if it passes through others.
Cas,
It is simply three letters,
But it makes this immortal feel
Even when he should not.
It makes him see
What he had never seen before,
But only if a certain mortal whispers his name.
Cas,
He should not feel,
But he does any way,
Even though it is just an abbreviation,
A simple pet name.
If you didn't realize/grasp, the "him, he and mortal" was Dean Winchester, an the "immortal and simple he (none italicized)" was Castiel.
