Jonathan and Sarah Adleta's children were doomed to a life of perverse cruelty before they were even born.

Jonathan Adleta, a former Marine officer, dreamed of the day he could have "daddy-daughter sex." After Sarah Adleta became pregnant with a daughter, he said he would marry her only if she agreed to let him carry out that desire. When the couple had a son, Sarah Adleta was expected to have sexual encounters with him.

In an Orlando federal courtroom this week, prosecutors and witnesses described, in disturbing and graphic detail, the heinous exploitation and abuse the couple's toddlers endured at the hands of their parents — even after they divorced.

Jonathan Adleta lived his dream until March, when the FBI received a tip that his 29-year-old former wife was communicating with a North Carolina man who was arrested on charges of having sex with a child.

That's when federal authorities began unraveling a cross-country web of sexual abuse that culminated in convictions for both parents — and could land 25-year-old Jonathan Adleta in prison for life.

Sarah Adleta, a University of Central Florida student, pleaded guilty in May to two charges of sexual exploitation of a minor. She faces 15 to 30 years in federal prison and will be sentenced next month. On Thursday, jurors found Jonathan Adleta guilty of two child-sex charges. He'll be sentenced in December and faces 10 years to life in prison.

The charges against him stem from abuse that occurred in December, when Sarah Adleta and the couple's two children traveled to his home in Oklahoma so he could have sexual contact with his daughter.

But to tell the Adletas' story, prosecutors had to take jurors to the beginning.

In opening statements, Assistant U.S. Attorney Karen Gable characterized Adleta as a father who had a "sexual appetite" for his own daughter.

Sarah Adleta testified that when she began dating Jonathan in 2008 — she was living with her family in Oviedo and he in an apartment in the Goldenrod area — he began showing her stories about fathers and daughters having sex, to gauge her interest in the possibility.

Their daughter was born in March 2009, and Sarah Adleta became pregnant with their son not long after.

Sarah Adleta, who testified for several hours this week wearing Orange County Jail garb, said she initially struggled with the concept and thought Jonathan Adleta would lose interest in it.

But she loved him, needed his financial security and said she would do whatever it took to not lose him, she told jurors.

Gable told jurors the couple made sex with their children "part of their parenting plan."

They married in 2010.

The marine was deployed to Afghanistan, and when he returned, the family moved to California, where he was stationed. There, his ex-wife said, he had more sexual contact with the children.

In late 2011, Jonathan Adleta filed for divorce, and Sarah Adleta later returned to Central Florida. But even with thousands of miles between them, she allowed her former husband to continue to prey on his daughter electronically through the videoconference program Skype.

By the spring of 2012, Jonathan Adleta had found a new girlfriend who agreed to let him victimize her daughter.

The girlfriend, 23-year-old Samantha Bryant — a Texas mother he met on a dating website — testified this week that she watched as Jonathan Adleta molested her daughter. On at least one occasion, she took pictures of the assault.

Bryant, who was visibly shaken and cried throughout much of her testimony, said Jonathan Adleta asked her to write fantasy-type stories about him having sex with his daughter and her daughter. She did. She also complied when he asked Bryant to perform sex acts on her own daughter.

Bryant was eventually charged with and pleaded guilty to sexually assaulting her daughter and allowing Jonathan Adleta to sexually abuse the girl.

In December, Bryant and her two children spent Christmas in Oklahoma with Jonathan and Sarah Adleta and their two children. Sarah Adleta told jurors that there, her former husband sexually abused their daughter in his bedroom and called her in to watch.

Sarah Adleta, who was emotionless during much of her testimony, began to choke up as she explained what she witnessed.

"She seemed very resistant," she said of her toddler, adding that the child was "really upset" and "frightened."

But Sarah rendered no aid to her crying girl.

Weeks later, after she and the children returned to Oviedo, Jonathan Adleta suggested that his former wife should find another man to abuse their daughter so she would become comfortable with the sex acts, to prevent her from 'freaking out" in the future.

During that time, Sarah Adleta was communicating with Aaron Dixon, a North Carolina man who was later arrested on child-sex charges in an unrelated case. She told jurors she performed sex acts on the children while Dixon watched via Skype.

In her closing argument Thursday, Gable told jurors that the last time the Adletas spoke, they discussed Sarah Adleta's taking their daughter to Dixon so he could sexually abuse the girl.

Jonathan Adleta, the prosecutor said, liked the idea.

apavuk@tribune.com or 407-420-5735