Some Hollywood couplings make you go, "Huh?" Take Jennifer Aniston and John Mayer for example. When Jen was married to Brad Pitt - that was hot. When she was linked to Orlando Bloom - that was interesting. But her pairing with John Mayer is, if it is anything at all, is probably just a passing fancy.

It's a fact that many celebrities enjoy keeping their options open. They may date for a while, but often the relationships end in heartache. Take Justin Timberlake. He dated both Britney Spears and Cameron Diaz. He's now linked to Jessica Biel. But unlike many stars who get hitched and divorced, Justin is content with long-term relationships. Why make a legal commitment when it's likely the relationship won't last?

Last December we predicted some celebrity divorces. Here are a few couples we think won't even make it down the aisle:

Pete Wentz & Ashlee Simpson
Newly engaged and on the heels of pregnancy rumors (and coincidentally a new album release), 23-year-old Simpson will likely follow in her older sister Jessica's footsteps. Jessica married, then divorced, pop star Nick Lachey. Although Ashlee recently commented that she enjoyed sharing her skinny jeans with Emo rocker Pete Wentz, is that enough to keep a relationship strong?

Paris Hilton & Benji Madden
Although it's sweet that Benji has written Paris a love song, it's been done before. And it doesn't guarantee a long-lasting relationship. ("Layla," anyone?) After just two months together, Paris and Benji are still in their honeymoon stage. But Paris is fickle. Remember her engagement to Greek shipping heir Paris Lastis? It lasted all of five months. How long will she stay with Benji?

Jake Gyllenhaal and Reese Witherspoon
The two co-starred in the box office disappointment "Rendition." It's been rumored that Jake is gay. Reese makes more money than Jake. What could be right with this relationship? And why are they rarely photographed together?

Jamie Lynn Spears and Casey Aldridge
She's 17. He's marrying her because she's pregnant. And this would work out because…?

Nicole Richie & Joel Madden
Yes, they have a beautiful baby named Harlow together. But a baby makes three doesn't guarantee a happy family. Good Charlotte rocker Joel Madden dated Hilary Duff before falling for Nicole. And Nicole was a notorious party girl before settling down with Joel. Have they changed their ways? Only time will tell.

Heidi Montag & Spencer Pratt
Reality TV stars Heidi and Spencer pose often for the paparazzi. Heidi made headlines last year for her breast implants. So, how long do superficial romances usually last?

Related stories:
Your 15 Minutes Of Fame Are Over: Go Away!
Hollywood's Latest Fashion Accessory: The Baby
Talentless Celebrity Spotlight: Paris Hilton, Nicole Richie & More

Story by Noelle Talmon contributing writer