IT was a "betrayal of trust" when a Sunshine Coast man moved into the home of his new partner and her family before he allegedly sodomised one of the children, a court has heard.
The man, who cannot be named to protect the child's identity, pleaded not guilty in Brisbane District Court on Tuesday to sodomising a boy five times and indecently dealing with him four times.
The crown alleged the accused sodomised the 12-year-old son of his female partner four times while the family were on holiday at Grandchester and at their home at Buderim.
The man is also accused of permitting the child to sodomise him in the spa of a holiday resort.
Crown prosecutor Ben Power referred to the situation as a "betrayal of trust."
"His actions were brazen," he said.
The man is also accused of indecently treating the boy, now 14 years old, at his mother's house in New Farm and at the Glasshouse Mountains.
The offences allegedly took place between May, 2010, and March, 2011.
Mr Power told the jury they would hear from the alleged victim's younger brother who would give evidence he once saw the accused man in bed with his brother.
Mr Power also alleged the accused allowed the boy to give him oral sex.
The allegations came to light when the alleged victim told his mother in April, 2011, and the pair went to the police.
Mr Power said the boy's mother claimed she did know about the behaviour but once woke up in the middle of the night to find her partner asleep on the floor of her sons' bedroom.
The court was closed on Tuesday while the alleged victim and his brother gave evidence.
The trial continues.