Belly Bumper
A belly bumper is a person who is unmotivated, lazy and/or lacks any sense of completion. A person who possesses this type of behavior can partake in said belly bumping activities.

A belly bump is also the clear act of two belly bumpers uniting!
That guy just belly bumped his way through work today!

Did you see those guys have an old fashioned belly bump.

He’s nothing but a belly bumper.