As Shania Twain copes with her sudden split with the support of family and friends in her native Canada, sources close to the singer say she is reeling from a double betrayal – not only by her husband of 14 years, music producer Robert "Mutt" Lange, but by a woman she considered a close friend. Lange's relationship with Marie-Anne Thiébaud, 37, a longtime secretary and house manager at Twain and Lange's estate in Switzerland, was behind the breakup, say several sources familiar with the situation. "Mutt and Marie-Anne left their spouses for each other and are still in a relationship," says one source, adding that the Swiss employee was a fixture in the household Twain, 42, and Lange, 59, shared with their son, 6-year-old Eja D’Angelo. "Their two families would vacation and spend holidays together," says the source. "Shania considered Marie-Anne one of her best friends." After the separation was announced, Lange told PEOPLE exclusively that an affair was "absolutely not the reason [for the breakup]... It's literally just a growing apart, that's all." He also denied that he was in a relationship with Thiébaud, saying, "It's not true."
Poor Shania. If true, this has to be really very difficult for her to deal with. The betrayal of a spouse or partner is already gut-wrenching but if that betrayal includes a best or close friend ... well, that just adds insult to injury. It is extremely unfortunate that this had to happen to Shania Twain (to anyone, really) and I can only hope that she'll be able to soldier thru this adversity and will emerge from this break-up a stronger person. I also hope that she takes her dog of an ex-husband to the cleaners in divorce court. [Source]