Hill Valley Clock Tower

During the act of "doggy style" you increase your thrust speed (to simulate getting up to 88 mph) and right before you climax you scream "1.21 Giggawatts" and promptly discharge a taser to your buttocks, thus transferring the electrical current to your partner, sending them back to the future.

"I gave her the Hill Valley Clock Tower, since then she can't think fourth dimensionally."
"Great Scott!"
"I know, this is heavy!"

Shartthrob

When you attempt to fart but instead shit starts to seep out so you quickly pucker up your asshole causing a pulsing sensation.

The other day when I was in line at the Apple Store I went to squeak one out but quickly realized it was a bad idea. The shartthrob was so painful my face contorted worse than my sphincter.