extra arm 

When two people are cuddling in bed, three arms have somewhere to be but the fourth arm is in the way. It's the extra arm.

"I've always wondered exactly what to do with that extra arm. I've tried curling it up between us, putting it above my head under the pillow, straightening it between us and the only thing that seems to work is just putting it behind me."
-- metafilter posting

extra arm by my name is Cos October 23, 2007