Costars that date(d): Blake Lively and Penn Badgley make it official

Now that Gossip Girl costars Penn Badgley and Blakey Lively have come out of the dating closet and confirmed their coupledom status, we all have to take pause to wonder: is this really a good idea? You know, don't poop where you eat? Though I'm no celebrity, I've witnessed a few work romances that ended in awkward silences in the elevator and avoidance of the cafeteria on taco day (everyone goes to the cafeteria on taco day). Usually things don't work out.

With that warning said, if you put a punch of attractive, single people together, something is going to happen, especially in Hollywood, where people are horny, savage beasts. There have been no shortage of costars that have met on the set and started a romance; some are still together, some have called it quits. Here are our favorites!

Nicole Kidman and Tom Cruise
This photo was taken back in 1999. They met on the set of Days of Thunder and before you know it, the beautiful Aussie and the too-short-if-he-weren't-famous actor fell on love. I think we were all fooled into thinking this was a marriage that would last forever! (Seriously, who saw Far and Away: how romantic was that movie?) However, we all know how the story ends: divorce, Katie Holmes, Oprah's Couch, Scientology, Suri.
Status: Divorced.


Courtney Cox and David Arquette
Though they met while making the horror flick Scream, there's certainly nothing horrific about their relationship (knock on wood). Courtney's cool demeanor and David's wacky, sometimes WTF personality seem like an odd fit that works together perfectly.
Status: Game on!


Adam Brody and Rachel Bilson
The costars of the O.C. dated for three years -- almost the entire run of the series. They even won the 2005 Teen Choice Award for "Best On-screen Chemistry"? How could a million teens be wrong? I personally thought this romance would stand the test of time, but as it is, love sucks and people break up. Harsh.
Status: Spilt. Rachel is rumored to be dating Hayden Christensen. Adam Brody...might need a job. (Where he been??)

Michael J. Fox and Tracy Pollen
Now here's a success story if there ever was one! These two met on the set of the super popular 80s TV show, Family Ties, got married in 1988 and have been happily in love ever since. This couple is so cute that I even forgive Tracy for stealing my man, Michael, who was my first girlhood crush. Alex P. Keaton was a dreamboat (even though he was a Republican).
Status: Game on!


Milo Ventimiglia and Hayden Panettiere
Their alter egos on the show Heroes (um, when is it coming back on air, NBC?) are invincible, but will their relationship be? It's too soon to tell, but Milo has made a habit of dating his beautiful costars. He dated Gilmore Girls actress Alexis Bledel before moving onto Hayden. It must be hard to be so incredibly handsome.
Status: Game on!