But a jury has cleared him of offences against the younger of the brothers, following less than two hours of deliberations.

The man, who cannot be named, has been on trial in the ACT Supreme Court this week over 12 indecent acts, allegedly committed either on or in the presence of the two brothers between 2011 and 2014.

The brothers were friends with the accused's children, and frequently slept at his home in Canberra's south.

The boys told the court of being regularly touched by their neighbour.

Their mother broke down as she gave evidence, saying she remembered her son once coming home late at night during a sleepover, bashing on the door, shaking and crying.

"He just hugged me and I hugged him," she said.

"I guess I knew something was wrong ... I had a gut feeling."

The man was found guilty of six indecent acts and not guilty of two relating to the older boy.

He was cleared of all four charges relating to the younger sibling.

His barrister, Jason Moffett, had argued the younger boy's evidence was deeply flawed.

That's because of a significant inconsistency with the testimony of his mother, who had told the court that things would have been different if she had found out about the abuse earlier.

Her younger son, Mr Moffett said, claimed he had told his mother on most of the occasions he was touched.

Mr Moffett also said one of the alleged incidents - a grabbing of the younger boy's penis for five seconds while the boy went up stairs with others around - could not have happened.

The man was remanded in custody, and will face sentencing at a later date.