To bring a girl home and wait for her to use your bathroom before jerking off on her pillow. You then proceeds to initiate intercourse - doggy-style - before pushing her face into the soiled pillowcase.
"Yeah, dude, she had no idea, but I was totally pillowing that chick last night."
"Awesome, you should save that pillowcase for next time."
To go around defecating on people's pillows. Easiest done to roommates that won't clean the kitchen before they leave for work, but can also be done to random people if you can find out where they live.