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In honor of Valentine's Day 2013, we though we'd take a look back over the dating history of some of Glee's most beloved stars. First up, it's Dianna Agron (Quinn). Though the gorgeous Glee starlet doesn't appear to be dating anyone right now, she's certainly been linked to plenty of Hollywood hotties over the years. Here's  quick look back over her love life.

Back in May 2012, photographers spotted Glee’s  attending a rock concert with a hot new guy: 29-year-old Henry Joost, a Hollywood director who’s was then working on the horror film Paranormal Activity 4.

Some photographers initially misidentified Henry as Dianna’s ex, Sebastian Stan, who she broke up with late last year. So what other hot Hollywood men have been linked to Dianna during her time in the spotlight? Well, there's James Franco's supercute younger brother, Dave Franco, for one. He and Dianna dated back in 2008-2009. Here’s a short history of Dianna's relationship past.

Alex Pettyfer: The British Bad Boy

Back in August 2010, Dianna landed a lead role in the sci-fi thriller I Am Number Four, and it soon became clear that she and co-star Alex Pettyfer weren’t just lovers on-screen. The sexy Brit raved about how “amazing” his GF was, and even came to visit her on the Glee set.

Dianna gushed that though Alex might “see himself as a bad boy,” he’s “actually very sweet in real life.” Rumors even flew that the two might have gotten engaged, though both Di and Alex denied any such talk.

Unfortunately, that’s when things started to go south. The couple split in February 2011, with reports emerging that Alex was a “little controlling” and “really paranoid” Dianna would cheat, even confronting Gossip Girl’s Sebastian Stan about a rumor he slept with Dianna.

Dianna promptly moved out of the house she and Alex had been sharing, and checked into a hotel under an assumed name. Reports flew that she was terrified of him, and even feared for her life.

Sebastian Stan: The NYC Heartthrob

Credit: Michael Wright/WENN.com;Stefanie Keenan/Getty Images

About a month before Dianna was first linked to Alex in August 2010, tabloid reports initially paired her with Sebastian Stan, then playing Carter Baizen on Gossip Girl and most recently known for his roles on Kings and Once Upon a Time. Yet when Dianna hooked up with Alex, rumors of a romance between she and Sebastian had seemed like little more than tabloid fodder.

Fast forward to to May 2011: about four months after Dianna’s messy breakup with Alex, reports emerged that Di had rekindled her old flame with Sebastian. By July, she was flying to New York City to spend more time with him. (Kissing, partying, sleepovers, that sort of stuff.)

After that summer, Dianna and Sebastian kept the romance pretty low-profile, until it surfaced in December 2011 that the trials of a long-distance had taken their toll, and the two had officially broken up.

However, rumors flew that the duo had rekindled their romance when they were spotted sharing a “steamy” kiss outside of an LA restaurant on Valentine’s Day.

Henry Joost: The Cute Hollywood Director

Credit: RHS/WENN.com

Now, almost five months later, Dianna is stepping out with a new man: 29-year-old Henry Joost, the director behind the 2010 documentary, Catfish, and the horror films Paranormal Activity 3 and 4.

The new couple made their public debut attending a Jack White rock concert on May 23, but the relationship still appears to be in its early stages. A source told JustJared that Dianna and Henry had “been getting to know each other for the past few weeks,” and that they were “taking it slowly.” In July, he also accompanied her to Italy for the Giffoni Film Festival.

Christian Cooke: The British Charmer

After over four months and no news if anything was still happening with Henry, photographers one day spotted Dianna walking down the streets of New York City, hand-in-hand with British actor Christian Cooke.

Christian, a 25-year-old actor who recently left behind the world of British TV for a role on the Starz series Magic City, will soon be seen in the 2013 movie Romeo and Juliet, where his character, Mercutio, will get killed by Gossip Girl star Ed Westwick's Tybalt. 

Howevever, there was never any confirmation that Dianna and Christian were dating, and we have heard absolutley nothing about him since then. That means either Di and Christian are doing a really good job of keeping their relationship a secret... or Di is a single lady once again! (Men of America, we know which one you're hoping it is!_