He strongly denied the accusations when giving evidence, saying he was not attracted to the woman and was happily married.
Under cross-examination by Crown prosecutor Robin Bates, he did acknowledge complimenting the woman's appearance on two separate occasions.
Bates argued the man did in fact harbour sexual feelings towards his niece, and that his actions escalated until the woman could no longer take it and left.
While there were no witnesses to the incidents, Bates submitted that they could have occurred without being seen by people in the vicinity.
He said the complainant had presented a "totally understandable and credible narrative" about what had occurred.
Counsel Anne Stevens QC took a different view, describing the woman's account as a fantasy, and that she was obsessed with the man rather than the other way around.
There was considerable evidence the woman's thinking was "delusional", Stevens argued.
She said there was no explanation as to why her client, a man of "impeccable integrity and good character", would suddenly become a sexual predator.
She also said the woman had plenty of opportunities to tell her aunt, and a friend, about the alleged incidents during her stay. She did not.
But, Bates said, the suggestion an alleged victim would tell the first person she saw what happened was an "outdated myth", because situations could be complex.
Judge Jim Large reserved his decision until this afternoon.
Sexual harm - Do you need help?
If it's an emergency and you feel that you or someone else is at risk, call 111.
If you've ever experienced sexual assault or abuse and need to talk to someone contact Safe to Talk confidentially:
• Call 0800 044 334
• Text 4334
• Email support@safetotalk.nz
• For more info or to web chat visit
www.safetotalk.nz
Alternatively contact your local police station -
click here for a list.