breathing blanket
A living breathing human being one shares a bed with; often a lover, who provides warmth in bed with hugs and cuddles, even in the absence of an actual blanket or duvet.
Agie: I had a cold sleepless night, Robert didn't come home.
Kate: oh, I'm so sorry, no breathing blanket to keep you warm...
Kate: oh, I'm so sorry, no breathing blanket to keep you warm...