The idea of "forever"
Is kind of like
A feather floating on water.
For a long while it'll rest on top of it
Like the spring time water striders.
All the while,
Slowly,
Over time,
The water will swallow each barb  
Until it's pressed flat to the surface,  
Still, it will take longer to disappear.
Akin to the blurred line
When  
Promised forever-mores begin to fade.
There is still hope
To pull the feather away,
Dry it to its former glory,
However,
The gentle current of the water pulls it,
Just out of reach.
All that's left now is to watch
As liquid seeps into the feather's
Hollow shaft and be devoured
Never to resurface.