While receiving oral sex, thrust your penis down your partner's esophagus when you reach the point of ejaculation. Your partner will try to scream at you for surprising/gagging them. And with your penis ejaculating in their esophagus, it will sound like a growling noise that will resemble Chewbacca from Star Wars.
I gave my girlfriend the Angry Chewbacca when I was drunk two weeks ago. Now we don't have sex anymore.