The length of supervision and monitoring were the maximum periods allowed by law.
Defence counsel Don Matthews did not opposes the order and highlighted the good behaviour of his client while in prison.
Justice Brewer said it was the ''appropriate and responsible'' option to put Harris under supervision to protect members of the community.
''I consider he has a high risk to commit sexual offending in the future,'' he said.
On two different occasions, in 2017 and 2018, Harris performed an indecent act in front of the two children in public places .
He was deported from Australia in 2016 for other sexual offending and had previous convictions.
Where to get help:
• If it's an emergency and you feel that you or someone else is at risk, call 111.
• If you've ever experienced sexual assault or abuse and need to talk to someone call the confidential crisis helpline Safe to Talk on: 0800 044 334 or text 4334.
• Alternatively contact your local police station
• If you have been abused, remember it's not your fault.