Brad Pitt has been angered by Angelina Jolie's demand to have sole custody of their six children, and has told friends she has "unleashed hell" by allowing damaging stories to emerge about his fitness as a parent.Pitt, 52, was said to be devastated by Jolie's decision to file for divorce on Monday, citing irreconcilable differences.And he is furious at swirling suggestions that she was concerned by his alleged alcohol consumption, marijuana smoking and anger issues.Jolie supposedly hired a private eye to follow Pitt on set with French actress Marion Cotillard - who is currently expecting her second child with her partner, actor Guillaume Canet - and is said to be "absolutely devastated" at being dragged into the circus. By awkward coincidence, a trailer for Allied, the steamy World War 2 spy drama starring Pitt and Cotillard, due out in November, was released on the same day as the divorce was announced.Pitt has reportedly told friends not to speak ill of Jolie, and praised her parenting skills.But her decision to demand sole custody, with Pitt only given visitation rights, was unacceptable to the actor.Pitt has told friends: "There's no chance that's going to happen," according to gossip site TMZ. The site reported that he said she had "unleashed hell" by allowing friends to discuss their relationship and he was now concerned for the safety of the children.The couple have three biological children - Shiloh, 10, and twins Knox and Vivienne, eight.The twins were treated to breakfast pancakes at a low-key café in West Hollywood to celebrate their birthdays in July.The couple also have three adopted children - Maddox, 15, from Cambodia; Pax, 12, from Vietnam; and Zahara, 11, from Ethiopia.Jolie was reported to have been upset by Pitt's strict parenting. She guest-edited BBC Radio 4's Women's Hour in June, and spoke about her children's upbringing, detailing the diverse languages and range of skills boasted by her brood."All the kids are learning different languages," she revealed."I asked them what languages they wanted to learn and Shi is learning Khmai, which is a Cambodian language, Pax is focusing on Vietnamese."Mad has taken to German and Russian, Z is speaking French, Vivienne really wanted to learn Arabic, and Knox is learning sign language."Maddox, her eldest child, is helping his mother work on a documentary - First They Killed My Father - about the war in his Cambodian homeland. "None of my kids want to be actors," she said. "They are actually very interested in being musicians. I think they like the process of film from the outside. Mad is interested in editing. Pax loves music and deejaying."Jolie and Pitt are said to have been arguing for some time and discussing divorce.But he was only aware of her decision the day before she filed the documents.She "feels like a weight has been lifted", a source told gossip magazine US Weekly. "This has been coming for some time. This is a very difficult period for the family."Jolie's lawyer, Robert Offer, would only say: "This decision was made for the health of the family. She will not be commenting and asks that the family be given its privacy at this time."George Clooney, a friend of the couple who was told the news by a reporter, said: "That's a sad story and unfortunate for a family. It's an unfortunate story about a family. I feel very sorry to hear that."Actor Jon Voight, Jolie's estranged father, told Inside Edition: "It's a sad thing. Say a little prayer. I am concerned for Angie and the children and hopefully I will be seeing them very soon." ..