When dropping a deuce, taking a dump, dropping the kids off at the pool, etc...the fecal deposit after flushing leaves an artistic swirl of streaks and smudges behind in the bowl resembling sections of marble.
"That was a heck of a dinner, Marge! I'm sure I'll be marbling the crapper tomorrow!"
The act of two males putting their ball sacks inside a cloth bag as you would hold marbles and tying it closed.
Person 1: i really want to have our balls together more than usual
Person 2: how bout we start marbling them?
Person 1: yes please, i love it when you're nestled inside me marbling our balls.