paint the canvas 

to ejaculate forcefully upon an object/person

I told Gilbert to paint the canvas all over Nooch's eager face.

paint the canvas by zachary timmerman December 13, 2009

Paint the canvas 

To succeed in leaving fecal residue on the toilet bowl after a flush.

Be right back, I'm gonna go paint the canvas.

Paint the canvas by kdwilco August 21, 2009