A pillow toy is another term for a self pleasuring device (more than likely to be a dildo) that is hidden underneath a pillow.
Me: "Dude I was cleaning my parents' room for money and when I was making their bed, I found a pillow toy."
Friend: "Haha. Really?"
Unchaining your pillow can be used in many different ways
Describing how beautifully poetic something is
or
to talk around NSFW topics
Example 1:
This poem was so beautiful, it unchained your pillow
Example 2:
I want to unchain your pillow later?
dude 1: i think i’m in love
dudette1: with who, bethany??
dude 1: no, pillow vibessss