All three children were friends of Surgeon and his family.
His sentence was increased by 11 months after he pleaded guilty to the third offence at trial, making his sentence a total of four years and six months.
Surgeon was also denied parole in 2018, 2019 and 2020.
At a hearing at Hawke's Bay Regional Prison earlier this month he was again denied bail.
At Surgeon's last parole hearing in September last year, concerns were raised as to whether the Short Intervention Programme was appropriate given his further offending and restrictions on release.
The Parole Board's psychological report stated that Surgeon could "get into a dark place and then becomes vengeful".
"He apparently has a poor ability to deal with stress. He still sees the world as somewhat unfair."
As a result, the board stated he remains an "undue risk and cannot be released".
It was suggested Surgeon needed further one-on-one counselling to deal with the issues raised in the psychological report, which was now being undertaken.
The board will see him again in August 2021, when it hopes to have a report on the work done with a psychologist, reassessing risk and assessing the "appropriateness" of his release plan.
Surgeon would likely be prohibited from going to Hawke's Bay, Wellington and Manawatū upon eventual release, the board said.
In September 2020, Surgeon told the Parole Board he didn't realise the contact he had with his young victims was wrong until after he was found guilty.