Brandi Glanville is fuming over rumors that she's having an affair with her ex-husband, Eddie Cibrian, reports RadarOnline.

The "Real Housewives of Beverly Hills" cast member took to Twitter to deny allegations that an affair with Cibrian led his current wife, LeAnn Rimes, to check into a rehab center.

"I'm NOT cheating with. Y ex husband I would never do that #EWWWWWW," Glanville wrote on Twitter on Sept. 9.

Glanville married Cibrian in 2001 and had two sons together. But in 2009, after Cibrian hooked up with Rimes while filming the Lifetime movie "Northern Lights," the two engaged in a affair, cozying up at restaurants and meeting for trysts. Rimes and Cibrian tied the knot in April 2011.

Understandably, Glanville and Rimes have a bitter relationship, but Glanville appeared to offer sincere support when Rimes entered rehab in August.

"I totally support LeAnn's decision to enter rehab. My top priority is my children and at the end of the day we are a family. LeAnn is their stepmom, and they love her. I am wishing her all the best and I hope she will find what she is looking for while in rehab," Glanville said in a statement to Us Weekly.

Despite her message of support, rumors that she's cheating with Cibrian to get back at Rimes still persist. Last week it was reported that part of the reason Rimes checked into rehab was Cibrian's tendency to cheat.

"LeAnn has had major insecurity issues since she first got together with Eddie," a friend of the couple told Us Weekly. "She's been stressed about always being called a home-wrecker and also worried that Eddie is cheating on her. She's been on a downward spiral."

Rimes apparently has good reason to worry, since Cibrian has cheated before. Before his relationship with Rimes, Cibrian allegedly cheated on Glanville in 2006 with a cocktail waitress named Scheana Marie.

Rimes checked into rehab for "stress and anxiety" at the end of August, and left treatment to perform three days of concerts. According to RadarOnline, the singer is due back in treatment on Monday.

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  • Angelina Jolie

    In 2004, Brad Pitt allegedly fell for his <a href="http://www.usmagazine.com/celebrity-news/news/what-jennifer-aniston-thinks-of-brad-pitt-angelina-jolies-engagement-2012264#ixzz1wrQN7P9U" target="_hplink">"Mr. and Mrs. Smith" co-star, Angelina Jolie</a>, while he was still married to Jennifer Aniston. A media frenzy ensued, and soon after <a href="http://www.people.com/people/article/0,,1042412,00.html" target="_hplink">filing to divorce Pitt</a> in March 2005, Aniston opened up about the split, as well as Jolie and Pitt's <a href="http://www.wmagazine.com/celebrities/archive/brad_pitt_angelina_jolie#slide=1" target="_hplink">photo shoot as a married couple in <em>W</em> magazine</a>. "<a href="http://today.msnbc.msn.com/id/8797298/ns/today-entertainment/t/aniston-says-pitt-missing-sensitivity-chip/" target="_hplink">There's a sensitivity chip that's missing</a>," Aniston said of Pitt in an interview with <em>Vanity Fair </em>.

  • Elizabeth Taylor

    After third husband Mike Todd died, Elizabeth Taylor <a href="http://articles.nydailynews.com/2010-09-26/gossip/29440604_1_harry-karl-crooner-eddie-fisher-reynolds-for-elizabeth-taylor" target="_hplink">reportedly found comfort in the arms</a> of Todd's best friend, Eddie Fisher, who was married to actress Debbie Reynolds at the time. Soon after leaving Reynolds, <a href="http://www.time.com/time/magazine/article/0,9171,2022650,00.html" target="_hplink">Fisher and Taylor married</a>, making him the screen siren's fourth husband. When asked about her role in the dissolution of Fisher's marriage, <a href="http://news.google.com/newspapers?nid=1948&dat=19580911&id=j-YwAAAAIBAJ&sjid=HeAFAAAAIBAJ&pg=2835,1438181" target="_hplink">Taylor reportedly said</a>, "You can't break up a happy marriage. Debbie's and Eddie's never has been." As for Reynolds, she's apparently moved on from the affair. "I don't blame Elizabeth now -- now that I have more of a brain about it. At the time it was just such a shock to me," the star <a href="http://www.oprah.com/oprahshow/Carrie-Fisher-and-Debbie-Reynolds/7#ixzz1wwsVYHbi" target="_hplink">told Oprah in February 2011</a>.

  • Gerard Butler

    Before leaving for a <a href="http://www.radaronline.com/exclusives/2012/02/gerard-butler-completed-rehab-home-good-health" target="_hplink">three-week rehab stint</a>, Radar Online alleged that Gerard Butler had <a href="http://www.radaronline.com/exclusives/2012/03/gerard-butler-broke-marriage-home-wrecker" target="_hplink">broken up the marriage</a> of an unnamed newlywed actress. "They would exchange heated text messages, emails and phone calls," an anonymous source told the site. "She thought Gerard wanted to be in a relationship with her but then she found out he was involved with other girls, and hadn't been exactly honest with her about what was going on in his life."

  • Tori Spelling and Dean McDermott

    Tori Spelling and Dean McDermott <a href="http://blog.sfgate.com/dailydish/2008/03/13/spelling-knew-her-marriage-was-in-trouble-after-cheating/#ixzz1OFbjMEQl" target="_hplink">reportedly slept together</a> the first night they met, though they were each married to different people at the time -- Spelling to actor Charlie Shanian and McDermott to Mary Jo Eustace, with whom he had <a href="http://www.people.com/people/article/0,,20040326,00.html" target="_hplink">just adopted a newborn baby</a>. Spelling <a href="http://www.people.com/people/article/0,,1117511,00.html" target="_hplink">divorced Shanian</a> in October 2005, merely 15 months after their $1-million wedding, and <a href="http://www.people.com/people/article/0,,1191681,00.html" target="_hplink">eloped with McDermott</a> the following May. In her book "<a href="http://www.huffingtonpost.com/2011/02/23/celebrity-divorce-memoirs_n_826871.html#s244474&title=sTORI_Telling_by" target="_hplink">sTORI Telling</a>," which was published in 2008, the actress wrote of her split from Shanian: "It needed to end, but it could have happened in a nicer way." Spelling and McDermott, who star in the reality show, "Tori & Dean: Home Sweet Hollywood," recently announced that they're <a href="http://www.huffingtonpost.com/2012/03/23/tori-spelling-pregnant-baby-4_n_1375807.html" target="_hplink">expecting a fourth child</a>.

  • Madonna

    In July 2008, Alex Rodriguez's wife, Cynthia Scurtis, <a href="http://sports.espn.go.com/mlb/news/story?id=3475674" target="_hplink">filed for divorce from the New York Yankees slugger</a>. In her filing, she accusing him of emotional abandonment, "marital misconduct" and extramarital affairs. According to <em>The Telegraph</em>, Scurtis believed the the three-time M.V.P. was having an affair with <a href="http://www.telegraph.co.uk/news/celebritynews/2251995/Madonna-blamed-for-Alex-Rodriguezs-divorce.html" target="_hplink">Madonna</a>, who was married to Guy Ritchie at the time. The popstar denied the claims, insisting that she and A-Rod <a href="http://www.telegraph.co.uk/news/celebritynews/2251995/Madonna-blamed-for-Alex-Rodriguezs-divorce.html" target="_hplink">were just friends</a>.

  • Russell Crowe

    In July 2000, Meg Ryan and Dennis Quaid <a href="http://www.ew.com/ew/article/0,,276771,00.html" target="_hplink">announced they were separating</a> amid allegations of an affair between Ryan and her "Proof of Life" co-star Russell Crowe. A month before the filing, Ryan and Crowe were allegedly seen "cuddling, hugging, kissing" on-set, a <a href="http://www.people.com/people/archive/article/0,,20131801,00.html" target="_hplink">source told <em>People</em> magazine</a>. Quaid and Ryan's divorce was <a href="http://blog.sfgate.com/dailydish/2008/09/29/quaid-denies-ryan-is-moving-for-full-custody-of-son/" target="_hplink">finalized in 2001</a>. Meanwhile, the actress' relationship with Crowe <a href="http://www.usmagazine.com/celebrity-news/pictures/stars-caught-cheating-2009318/2771" target="_hplink">reportedly fizzled out</a> after a few months.

  • LeAnn Rimes And Eddie Cibrian

    In April 2009, rumors surfaced that LeAnn Rimes and Eddie Cibrian -- both married at the time -- were <a href="http://www.huffingtonpost.com/2009/03/17/leann-rimes-and-eddie-cib_n_176129.html" target="_hplink">having an affair</a> on the set of television movie "Northern Lights." Cibrian released a statement <a href="http://www.huffingtonpost.com/2009/03/17/leann-rimes-and-eddie-cib_n_176129.html" target="_hplink">denying the accustations</a>, while Rimes neither denied nor confirmed them. But, by December 2009, Rimes' husband, Dean Sheremet <a href="http://www.huffingtonpost.com/2009/12/19/leann-rimes-husband-files_n_398050.html" target="_hplink">had filed for divorce</a> -- a move that came just three months after Cibrian <a href="http://www.huffingtonpost.com/2009/12/19/leann-rimes-husband-files_n_398050.html" target="_hplink">split from Brandi Glanville, his wife of eight years</a>. Rimes and Cibrian <a href="http://www.huffingtonpost.com/2011/04/23/leann-rimes-eddie-cibrian-married_n_852841.html" target="_hplink">wed in April 2011</a>. Rimes later opened up about the circumstances <a href="http://www.huffingtonpost.com/2011/04/25/leann-rimes-on-affair-wit_n_853535.html" target="_hplink">surrounding her split and remarriage</a>, telling Great American Country, "I didn't have the tools to know how to do it the right way... I'm not glad it happened, but I know why it did."

  • Sienna Miller

    In 2008, Balthazar Getty had a highly publicized affair with Sienna Miller, culminated in a <a href="http://www.popsugar.com/NSFW-Topless-Photos-Sienna-Miller-Balthazar-Getty-Italy-1796219" target="_hplink">series</a> <a href="http://www.popsugar.com/Photos-Topless-Sienna-Miller-Balthazar-Getty-1787723" target="_hplink">of NSFW photos</a> of the pair enjoying an Italian getaway. Getty and his wife, Rosetta, soon separated, but by September 2010 the Gettys were <a href="http://www.huffingtonpost.com/2010/09/20/balthazar-getty-wife-rose_n_731137.html" target="_hplink">back together and opening up to <em>Harpers Bazaar</em></a> about the "challenging time" in their marriage. "I loved and missed my family too much not to make it work," the actor told the magazine.

  • Ben Affleck

    Ben Affleck and Jennifer Lopez met on the <a href="http://www.usatoday.com/life/people/2004-01-23-bennifer-timelilne_x.htm" target="_hplink">set of box-office bomb "Gigli" in early 2002</a>, while Lopez was married to second husband, Cris Judd. Three days before Lopez filed for divorce from Judd in July 2002, <em>People</em> reported that the actress was already introducing Affleck as her "<a href="http://www.people.com/people/archive/article/0,,20137732,00.html" target="_hplink">new boyfriend</a>" to friends. Though the pair known as Bennifer became engaged in November 2002, the relationship was over for good <a href="http://www.usatoday.com/life/people/2004-01-22-bennifer-breakup_x.htm" target="_hplink"> by January 2004</a>.

  • Evan Rachel Wood

    Dita Von Teese filed to divorce rocker Marilyn Manson in December 2006, after one year of marriage. Sources told <em>People</em> magazine that Manson's <a href="http://www.people.com/people/article/0,,20007918,00.html" target="_hplink">relationship with the Evan Rachel Wood played a part</a> in Von Teese's decision to file for divorce, though Wood claimed that she and Manson were merely <a href="http://www.people.com/people/article/0,,20045566,00.html" target="_hplink">"movie buddies" and only got together after</a> he and and his wife had split. Manson and Wood <a href="http://www.people.com/people/article/0,,20335115,00.html" target="_hplink">became engaged</a> in January 2010, but by <a href="http://www.people.com/people/article/0,,20413552,00.html" target="_hplink">August 2010</a> the pair had reportedly gone their separate ways.

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