During doggy-style sex, you attempt to switch to anal. When met with resistance and have successfully penetrated, you tase the woman as she trys to pull away, like she's trying to cross an invisible fence.
She'll learn, they always do.
The tasing causes immediate ejaculation for the male.
"Her asshole was taunting me.... I just had to throw it in. I knew it wasnt gonna fly, so as soon as I got it in, I pushed her up to the invisible fence."