The 36-year-old man had developed an addiction to child pornography and was battling problems with alcohol around the time of the offences, the ACT Supreme Court heard on Monday.

Justice John Burns said the man, whose name has been suppressed, had made the ''very rare'' decision to tell his wife about his actions and turn himself into police.

He pleaded guilty to five counts of indecently assaulting a child under 16.

The man had gone into the children's bedrooms at night while they were asleep and touched their genitals without them knowing over six weeks last year, the court heard. He had confessed his actions to his wife and reported himself to child-protection services and the police soon after.

The offender also sought counselling and signed up to a 12-step program with Sexaholics Anonymous.

The Crown argued the man's preference for child pornography and repeated offending suggested he had a sexual interest in children, and meant he should serve time behind bars. But forensic psychologist Dr Bruce Stevens said from the witness box he would not class him as a paedophile.

Dr Stevens said his client was essentially a good person who had suffered ''a terrible loss of control'' due to his addiction to online child pornography. He said the man was not a typical sex offender as he had good social skills, a solid job and no previous criminal history.

Dr Stevens said there was a low risk the man would re-offend and he had good prospects for recovery if he continued with counselling.

The man's lawyer told the court the charges had a significant effect on his client's life. He had lost his job as a schoolteacher, was banned from seeing his stepchildren and was listed on the child-sex-offender register.

Justice Burns said while the offences were extremely serious and a significant breach of trust, they fell in the middle of the range for such acts.

Given the man had admitted guilt and demonstrated considerable remorse, a suspended prison term would be adequate, Justice Burns said.

He sentenced the man to one year and six months in prison, to be suspended upon entering an 18-month good-behaviour bond.

Justice Burns ordered the man to continue to take part in rehabilitation programs, including the territory's adult-sex-offender program.