WESTPORT — Police say a teenage boy was sexually assaulted by a Westport psychotherapist.

Two weeks ago, Woods Grove Road resident Kenneth Cardillo, 67, was charged with two counts of fourth-degree sexual assault. Now, a newly unsealed affidavit explains the circumstances surrounding Cardillo’s arrest.

On Jan. 14, Westport police arrived at a town residence on report a teenage boy was sexually assaulted that morning by his family therapist, Cardillo, at the boy’s home, Westport Police Detective Erin Shaw wrote in the affidavit.

A family friend reported the incident after receiving a text message from the boy saying Cardillo had sexually assaulted him.

The boy had underwent a medical procedure on his genitals, and that morning Cardillo, who served as the boy’s therapist for the past four years, unexpectedly arrived at his home, the boy told police.

The boy, referred to in the affidavit as male victim or “MV,” told Cardillo his genitals hurt. Cardillo offered to look at them and and the boy said that was OK, the affidavit reads.

Cardillo allegedly offered to help, and then rubbed the boy’s genitals with cooking oil and then with lotion. Cardillo also applied pressure to the genitals, the affidavit says.

“MV stated while it was happening he just froze, didn’t know what to do and couldn’t believe it was happening,” the affidavit says.

Throughout the day, the boy corresponded with several friends and his father about what happened, including the family friend who reported the incident to police.

In an interview with the boy’s father, police said Cardillo had recently helped his family with home counseling visits and assistance with household chores. The father said he asked Cardillo to go to the home at 9:30 a.m. that morning to speak with a contractor because he would be at work.

The father said he received a text from Cardillo around 11 a.m. saying he discussed the boy’s genitals with him, but did not disclose that he physically touched the boy.

“MV’s father admitted he was very confused at MV’s initial allegation because he was in disbelief that Cardillo would do something like this after being so helpful with his family,” the affidavit reads.

In his account, Cardillo, who has worked as a family counselor for over 35 years and is a licensed psychoanalyst, said he asked the boy if it was OK for him to touch his genitals, and that the boy said yes.

“I asked Cardillo at the scene why MV couldn’t have applied the treatment himself, and Cardillo stated he felt he was helping MV in a paternal manner as he would have his own children,” Shaw wrote in the affidavit. “Cardillo stated he believes he held the family together as primary caregiver. He labeled himself multiple times in various ways as the ‘king grandfather,’ not the ‘creepy grandfather,’ then as the family counselor but then not as a counselor.”

“Cardillo said there was no sexual gratification on his part, neither of them had an erection and that there was no other contact ... other than him touching and treating the penis,” the affidavit says.

Following the police interview, Shaw said Cardillo admitted to police his actions were a misjudgment.

In the arrest report, Cardillo’s address is listed as 18 Wood Grove Road, which is the same address as the Westport School of Music. A representative of the school said she could not comment on whether Cardillo lived at the site and said pending litigation prohibits her from speaking on the manner. Attorney Andrew Bowman is said to represent Cardillo.

“Ken Cardillo is presumed innocent and we will deal with his case in court,” Bowman said.

svaughan@hearstmediact.com; 203-842-2638; @SophieCVaughan1