She hasn't been dating him very long but that didn't stop Jennifer Aniston from introducing new guy Justin Theroux to her friends this past weekend.A source tells PEOPLE that the 'Horrible Bosses' star threw a little party last Friday night and used it as an opportunity to introduce Theroux to some of her closest buddies, including Courteney Cox and Chelsea Handler "They all had a great time and enjoyed Justin's company," the source told PEOPLE. The couple, which met last fall while making the upcoming film, 'Wanderlust,' are "doing great," the source added. "He's edgier than the guys Jen usually dates. She really likes him!" ||||| The Breakup, starring Jennifer Aniston and . . . Courteney Cox? 
 
 Although the actresses have been best friends through thick and thin since the 1994 debut of, er, Friends on NBC, they haven't been photographed together in nearly a year. 
 
 PHOTOS: Jen and Courteney friendship -- a timeline 
 
 "There's tension" between Aniston, 42, and Cox, 46, one source confirms in the new Us Weekly, out now. 
 
 What could possibly threaten such a close-knit friendship? Cox's trial separation from hubby David Arquette as she hangs with sexy Cougar Town costars Brian Van Holt and Josh Hopkins. 
 
 PHOTOS: Shocking best friend breakups 
 
 "Jen thinks Courteney is acting callous by running around with this guy but refusing to file divorce papers," an Aniston source says. "Like she's playing mind games with David." (Cox and Arquette announced their trial split in September 2010 after 11 years of marriage.) 
 
 Cox's post-separation antics with her costar even reminded Aniston of her own marital heartache with ex Brad Pitt, who took up with Angelina Jolie weeks after their 2005 split. 
 
 PHOTOS: A look back at Brad and Jen's good old days together 
 
 "She hates watching Courteney do the same thing," the source says. 
 
 Can this friendship be saved? Read more about this shocking rift in the new Us Weekly -- on stands now. ||||| Courteney Cox and Brad Pitt Meet for Dinner 
 
 Email This joined his ex-wife's best friend 
 
 
 
 The two stars joined 12 other people at Hollywood hotspot Beso for a dinner party celebrating their manager Cynthia Pett-Dante's birthday, 
 
 
 
 "They hugged and kissed when they greeted each other," an onlooker told PEOPLE. "They talked for a while." 
 
 
 
 "They were chatting, catching up," the witness added. "They both seemed happy and totally relaxed, very at ease. And they were both smiling the entire time. It didn't seem awkward at all." Brad Pitt joined his ex-wife's best friend Courteney Cox for dinner on Wednesday--but it's not as scandalous as it sounds.The two stars joined 12 other people at Hollywood hotspot Beso for a dinner party celebrating their manager Cynthia Pett-Dante's birthday, PEOPLE reports. In fact, 'Eastbound and Down' star Danny McBride was also there."They hugged and kissed when they greeted each other," an onlooker told PEOPLE. "They talked for a while.""They were chatting, catching up," the witness added. "They both seemed happy and totally relaxed, very at ease. And they were both smiling the entire time. It didn't seem awkward at all." 
 
 http://xml.channel.aol.com/xmlpublisher/fetch.v2.xml?option=expand_relative_urls&dataUrlNodes=uiConfig,feedConfig,entry&id=691977&pid=691976&uts=1273167996 http://www.popeater.com/mm_track/popeater/music/?s_channel=us.musicpop&s_account=aolpopeater,aolsvc&omni=1&ke=1 http://cdn.channel.aol.com/cs_feed_v1_6/csfeedwrapper.swf PopScene: Week's Hottest Pics Gabourey Sidibe attends The American Cancer Society's Choose You luncheon on May 5th in New York City. Amy Sussman, Getty Images Amy Sussman, Getty Images PopScene: Weeks Hottest Pics 
 
 Cox and Pitt didn't sit next to each other at the meal but did get to spend some time together catching up. No word on whether they chatted about Jennifer Aniston . The eyewitness also reports that Pitt chowed on a steak and sipped a beer and even sat at the bar with the patrons for a little bit. "He was really cool."
– Friends stars Jennifer Aniston and Courteney Cox have been famous for being real-life friends ever since the show debuted in 1994. So why haven't they been photographed together in almost a year? Sources tell Us "there's tension" between them, and not because Courteney had dinner with Brad Pitt last month. No, it stems from Cox going out on the town with her male costars during her trial separation from hubby David Arquette. "Jen thinks Courteney is acting callous by running around with this guy but refusing to file divorce papers," an Aniston source says. "Like she's playing mind games with David." The source adds that the whole thing reminds Jen of her own ex-husband taking up with Angelina Jolie after they split: "She hates watching Courteney do the same thing." But click here for a report that Jen recently introduced her new boy toy to friends ... including Cox.