When you're giving it to a girl from behind, and you're about to erupt you're baby yogurt, you pull out and spin around and unload your baby cannon into her mouth and face fuck her, leaving a surprised expression on her face, looking like an Egyptian howler monkey howling into the moonlight.
Specifically used when a woman doesn't like to swallow - after a man shoots his load into a woman's mouth, he immediately pulls out and pinches her nipple, causing her to howl in pain as she gargles on the cum – sounding like Chewbacca
Disappointed with the fact that his new woman doesn't swallow, Mark decided to top off the blowjob with a Chewbaccan Howler.
The act of regurgitating on ones penis for the purpose of lube, in leu of KY jelly (or other various lubes). First tried in Portland, OR; and the stomach acid burns the receiver's vaginal or anal areas making them blurt a ghastly howl.
Ben: "Dude, I was in a pinch so I pulled a Portland Howler."
Henry: "Did it hurt?"
Ben: "It tingled a little bit, but she was howlin'!"