An Iowa psychologist who treated the state’s most dangerous sex offenders has been accused of developing an “emotional affair” with a violent predator — even watching pornography with him, according to a disturbing new report.

Shannon Smith Sanders, 38, director of the treatment program at the Civil Commitment Unit for Sex Offenders in Cherokee, violated boundaries and did special favors for the offender — who grew obsessed with her, according to a Sept. 16 termination letter obtained by the Associated Press on Tuesday.

The patient was not identified, but attorney Jason Dunn told the AP that it was his client, Jeffrey Goodwin, 55, who is being held in connection with a 1988 sexual assault in Keokuk.

Sanders had encouraged Goodwin to masturbate in front of her and the two watched pornography together at least once, Dunn claimed.

Goodwin grabbed Sanders’ buttocks a couple times, and ended up developing a deeply personal relationship with her, involving sexual discussions, Dunn said. His client even sent the therapist notes written in code, he claimed.

“She had Jeff so wound up that he was willing to kill himself or someone else if he dishonored her or someone else dishonored her,” Dunn said in an interview. “He was really going crazy.”

The termination letter revealed that Sanders shared secrets with the patient, did not apply the institution’s rules to him, lied to protect him and failed to report his developing feelings for her.

Those actions created potential security concerns at the facility, which holds about 120 violent sexual predators who were ordered locked up for treatment following the completion of their prison terms.

His alleged relationship with Sanders developed this year after he returned to the facility after completing a sentence at the Anamosa State Penitentiary.

Goodwin filed a complaint against Sanders in June after he came to believe she was manipulating him — telling the offender she’d deny everything to protect herself if their illicit relationship was discovered, Dunn said.

Sanders worked as the facility’s treatment director for four years — earning nearly $98,000 last year, records show.

She declined to comment to the Associated Press.

With Post wires