The pairing is Michael and Lucifer and it's a tanka from each POV. This was also originally a tumblr post (as are all the other SPN poems I'll be posting; just to irk the Destiel shippers).
Michael:
It had to be done
You disappointed Father
I did what was asked
I did not wish this for you
I wish I could change the past
Lucifer:
We're no longer kids
I won't let you pity me
You've no idea
How much pain you inflicted
When you turned your face away
Gosh, Michael, you're so full of yourself. "I, I, I." It's not all about you!