A boy rejected attempts by a Catholic brother to tuck him into bed during a home prayer meeting thinking it was "weird and strange", a court has been told.
But prosecutors allege the boy's brother was indecently treated by Frank Terrence Keating the same night.
The alleged victim and family members testified in the 79-year-old former Catholic brother's committal hearing in Brisbane Magistrates Court on Monday.
Keating is charged with 18 counts that include indecent dealing, indecent treatment and carnal knowledge of any person against the order of nature.
Prosecutors allege he committed the offences - against four boys and one girl - while teaching at a Queensland school in the 1980s.
Keating was due to face a further 15 counts relating to another person but the Crown withdrew those at the start of the hearing.
An alleged victim's father told the court his son's behaviour changed after Keating, also known as Ibar, visited their house once in 1986.
"I did notice around that time his behaviour ... sort of took a left turn," he said.
The man said his son was "on track" but then started to deviate and eventually was in all sorts of trouble.
He did not recognise at the time that something had happened that night, but on reflection recognised it was about then, he told the hearing.
The brother of the same alleged victim told the court Keating came to his bedroom during a prayer meeting at their house.
In response to being asked what he wanted, Keating told the boy: "I just want to tuck you in," police were told.
The boy responded: "No, I'm asleep, get out and shut the door", he said in a statement to police.
The brother also told police Keating asked about the location of the boys' rooms.
"I thought it was weird and strange he wanted to tuck me in," he added in his statement.
Keating's lawyer Terry O'Gorman conceded during Monday's hearing there was a case against his client in relation to eight charges involving two people.
The committal hearing continues before magistrate Peter Saggers.
