Gregory Webb, 60, was handed a two-year prison sentence in Melbourne's County Court on Thursday, but won't spend a day behind bars provided he's of good behaviour for three years.

The Horsham man pleaded guilty to six charges of indecent assault against two teenage boys, dating back to the 1970s when he was aged between 18 and 20.

His lawyer Paul Smallwood said Webb was the subject of ongoing investigations into allegations made by three children, but said no charges had been laid.

He said there was no legal requirement to tell the court, but Webb had asked that he raise it and be candid.

Judge Gerard Mullaly said the historical abuse offences for which he was sentencing Webb were abhorrent and had stolen the innocence of children, then aged between 12 and 15, which was no small thing.

The first boy was abused at his family home and while on holidays. One one occasion Webb lay beside him on his bed and circled his nipples, telling him that's what he was to do with a girl.

That victim was in court to confront Webb, telling him he felt disgusted at being used for Webb's sick pleasure.

He said the abuse was under the guise of Webb teaching him what to do sexually with girls.

"It killed my confidence when I was actually with a girl," he said.

The victim said now when he thinks back to his otherwise happy childhood he can only think of "a sweet little boy being groomed and trained".

The memory of his elderly father crying as he revealed he had been "preyed upon by a parasite" would never leave him, he said.

A second boy was abused by Webb in a car at a drive-in movie theatre.

Mr Smallwood said Webb had suffered a health condition which left him with post-traumatic stress disorder.

He is also hearing impaired and cares for his vision-impaired wife and visits his 90-year-old father in aged care daily.

Judge Mullaly said Webb was a vulnerable man and accepted prison would be onerous.

He warned he would be immediately jailed for the full two years if he reoffended in the next three years, adding for the sake of Webb's own moral compass he should never re-offend.

Webb has been registered as a serious sex offender for life.

Australian Associated Press