What Key?

I find these little things
Lying around like souvenirs
But I'm not going to take them
I step further in
But I don't shut the gate behind me
I'll let you do that
Your chambers, your choice
Feeling your breath encompass me
Like a company of wraiths
I have a strong feeling
That it's only a matter of time

Only a matter of time
Before you lock me up
There will be no throwing away the key, though
No swallowing it or burying it
There is no key
See, I'm in you for good
And your deepest prisons
Will digest me however you see fit
Violently, I can take it
A big part of me aches for it
Softly, I can enjoy it, too
For every bit of me
That deserves incarceration
There's something that warrants absolution

But I won't be absolved by you
Not before I am judged and executed
In your gallows I'll perish, happily
Behind the bars of your bones
And upon the bare floor of your deepest tomb
There, here, I shall fester just as I thrive
Nibbling on the hand that feeds
For I can tell by the way your insides fluctuate
That you savor this sentencing just as well