A Kirkland man whose mother was charged with incest for having sex with him as an adult is a convicted child molester.

The 33-year-old man was convicted of second-degree child molestation and one count of sexual exploitation on May 24. According to charging documents, he admitted he gave his underage relative about 10 showers over a two-year period. He said he touched her inappropriately, but said he gave her showers for “clinical” purposes. He also said he photographed the girl with his cell phone.

The man, who is currently under court supervision, served 90 days in jail and must undergo five years of sex offender treatment.

The details of the son’s relationship with his mother came to light after he divulged the information to his therapist, who was required to report the abuse to law enforcement under the mandatory reporting law, said Dan Donohoe, spokesman for the King County Prosecutor’s Office.

The son, who was given up for adoption as an infant, said he found his mother through an adoption agency in 2004. Katheryn Thornton, 54, invited her son to move in to her Kingsgate home and said she had an 18-month sexual relationship with him, according to court documents filed last month.

The mother pleaded not guilty to the incest charges on Aug. 31 at King County Superior Court.

Both the mother could face a year in prison and be required to register as a sex offender, if convicted. Thornton returns to court for a case setting hearing on Sept. 14.