SINGAPORE - A retiree on trial for sexually assaulting a 12-year-old boy at a park toilet in Tampines last year said on Thursday (July 20) that the boy had made sexual overtures to him.

Taking the stand on the third day of his trial, Chua Hock Leong, 63, who is married with grown-up children, denied that he had performed oral sex on the Secondary 1 student on Jan 27 last year.

The prosecution's case is that Chua had befriended the boy, who was waiting for his friend to be dismissed from school, and asked him to go to the Tampines Eco Green park with him.

At the park, the boy was relieving himself inside the cubicle for the handicapped when Chua allegedly barged in and performed oral sex on him. After a minute, the boy pushed Chua away and ran off.

His mother later reported the alleged sexual assault to the police.

Chua's DNA was found on the inside of the boy's boxer shorts and the door handle of the toilet. Two palm prints lifted from the door handle also matched Chua's left palm.

On Thursday, Chua took the stand to give his side of the story.

He testified that the boy had called out to him and asked him: "Uncle, want to play or not?" Chua said he took "play" to refer to sexual activities.

He said the boy then suggested to "go 81", which he understood to mean taking a room at Hotel 81. Chua said he dismissed this because registration was required.

Chua said he continued chatting to the boy, who suggested going to the park. Chua said he did not know the way so he followed the boy there, while they continued to talk about sex.

At the park, he said they went into the toilet together and after relieving himself, the boy, with his trousers unzipped, told him he wanted to play. Chua said he declined because there were CCTV cameras in the toilet.

Chua said they then walked to another spot where he masturbated in the bushes while the boy kept a lookout. He said the boy touched his semen.

The boy then asked him for money, he said, so he fished out nearly $2 in coins from his bag and handed them to the boy.

When defence counsel Vijay Kumar asked him to explain how his DNA ended up on the boy's boxers, Chua said their hands were wet and he had given money to the boy. He did not elaborate.

In cross-examination, Deputy Public Prosecutor Stella Tan pointed out that the boy was then wearing a pair of PE shorts with no zip. Chua said he could have been mistaken.

The DPP then questioned why Chua did not give this account to the police earlier when he knew he was facing a sexual assault charge.

Chua replied that he was not listening properly in court and did not know what he was being charged with. "At the time I was confused because I was locked up for nothing."

He agreed with the DPP that it was all in his own mind that "play" alluded to something sexual.

Asked by his lawyer to explain why he did not give his account to the police, Chua said he felt "shameful" to tell the police that, at his age, he was masturbating in public.

Both sides will make closing arguments on Friday (July 21).

If convicted of sexual assault by penetration, Chua could be jailed for between eight and 20 years. He cannot be caned as he is above 50 years old.