Jennifer Aniston Goes Public With New Boyfriend Justin Theroux

No Hollywood beauty has been portrayed as unluckier in love than Jennifer Aniston, 42, who has borne the brunt of the love police's abuse since her 2005 split from Brad Pitt, 39, but now the actress is flaunting a brand new beau, Justin Theroux, 39, her costar from the upcoming Wanderlust.

The new couple made their first public appearance together on Sunday night at an MTV Movie Awards afterparty in Manhattan, hosted by Jason Sudeikis and also attended by Cameron Diaz, Alex Rodriguez, Reese Witherspoon, Chelsea Handler, Andrew Garfield and countless other A-listers. Aniston also starred alongside Sudeikis in this year's Horrible Bosses, but her attention was totally fixed on her date throughout the evening.

"Jen and Justin seem totally into each other and comfortable around one another," reports E! Online. "Jen was going around and introducing him to people, and while they would sometimes go have separate conversations, they always wound up back by each other's sides holding hands." Last month a rep for Aniston told the UK's Daily Mail that the duo were "just good friends," but that appears to have changed.

Aniston has been known to fall for her costars before. She and Vince Vaughn had something going on in 2006 after filming The Break-Up together, and she was even rumored to have been linked to Gerard Butler after last year's The Bounty Hunter. The night before debuting Theroux, the fit and fab actress also nabbed the Decade of Hotness award at Spike TV's Guys Choice Awards.

Wanderlust, which also stars Paul Rudd and Ray Liotta, is set to hit theaters on October 7.