In their People cover story, super-close star siblings Derek and Julianne Hough open up about their parents’ “difficult” divorce— and now Breaking Celebrity News can reveal exclusive details about the devastating split.

In Marriann and Bruce Hough’s official divorce decree, written in March 1998, when Derek was 12 and Julianne was just 9 years old, the couple vowed they would remain dedicated to their four minor children. (Marabeth is now 34, and Katherine is 32. The siblings also share an older sister, Sharee.)

READ the Hough family’s divorce decree

“The parties both have loving and valuable relationships with their children, and agree to work together to support those relationships,” Utah court documents state. “Further, the parties agree to work together to provide for the physical care and financial and emotional support of the children.”

However, according to documents, Derek, 29, and Julianne, 25, were promptly separated into different homes.

While both parents held joint legal care, “the Mother should provide the physical residency for Julianne and Katherine, and the Father should provide the physical residency for Derek and Marabeth,” papers say.

Derek and Julianne were once again brought together the following year when their parents sent the budding ballroom dancers off from their native Utah to London dance school Italia Conti Academy of Theatre Arts.

Despite the reunion with her brother, Julianne says she still suffered: In a 2013 Cosmopolitan interview, the actress says she was mentally and physically a