The Crown says a 38-year-old Marton man befriended a 9-year-old boy and took advantage of him for sexual gratification.
But Richard James Parkinson has denied two counts of an indecent act with a child.
His trial began in the Wanganui District Court yesterday before Judge David Cameron and a jury of eight women and four men.
The alleged offending took place in Marton in 2011 between August 1 and September 20.
The boy said Parkinson "was nice, but not nice for a good reason".
He said he met Parkinson as he walked home from school one afternoon with his uncle.
The defence said Parkinson accepted his family did befriend the boy but denied outright the alleged sexual offences.
Lawyer Peter Brosnahan said: "It did not happen."
The boy said Parkinson would buy him Lotto tickets and banana-flavoured milk.
He said he had often stayed overnight at Parkinson's house.
The boy said Parkinson would wander around the house with no clothes on after showering.
Parkinson is also accused of watching pornography in front of the child.
Eventually, the Crown alleges, Parkinson asked to see the boy's "private part".
Crown prosecutor Megan Jaquiery said the complainant consented - not because he wanted to, she said, but because he was bribed. Ms Jaquiery said Parkinson offered to pay for the child's membership to Club Penguin, an interactive online video game.
The second incident was similar, she said.
Parkinson allegedly asked the boy to touch him indecently in return for paid membership to Moshi Monsters, another internet-based computer game.
On October 4, 2011, the boy described the offending in an interview with a Child, Youth and Family social worker in Wanganui. That interview was played to the court yesterday afternoon.
Mr Brosnahan asked jurors to remain open-minded.
He said the way the allegations came to be made, the boy's home life and evidence from Parkinson's wife would play key roles in the defence's argument.
The trial continues today.By Aaron van Delden of the Wanganui Chronicle