A person who engages in sexual activity with a pillow, often their own pillow, imagining it as the person they fantasize about. Typical behavior of young boys with unmet sexual desires, in their early stages of exploring the bees and the birds.
In the middle of the night Dad: Whats that noise coming from juniors bedroom?
Mom: Its our little pillow fucker in action!
A person who has sex with a pillow. Generally these people are virgin males who can't "score" with an actual woman. So, he must make do with his pillow.