The defendant had been on a boozy rugby trip on July 8, 2018, and was dressed in a Batman costume for the event, the court heard at trial.
When the victim realised he had no way of getting home, she said he could stay at her house in another room.
Wetere was in such a state of intoxication, the woman had to take off his shoes and put a blanket over him.
She fell asleep too, but woke about 2.30am to find the man violating her.
The victim gave evidence at trial that she had frozen and told the jury she "couldn't get any words out".
When Wetere finished, she "just shut down" and went back to sleep, she said.
However, he repeated the ordeal again nearly eight hours later.
Again, the victim said nothing.
The court heard she showered and prepared breakfast for Wetere before dropping him at home.
After speaking to a friend later that day about her experience, she went to the police and made a statement.
When interviewed shortly after, Wetere said the entire evening was a "blackout" and he claimed not to recall any sexual activity.
Stevens highlighted before the Court of Appeal the woman's lack of verbal or physical protests but it did not find favour with Justices Christine French, Matthew Muir and Rebecca Ellis.
"The fact that there was no evidence that the appellant knew she was asleep cannot be relied upon as a reasonable basis for a belief in consent as he also did not know she was awake," Justice Muir said.
There was no sexual history between the pair, the court heard.
"The absence of protest from the complainant, whether verbally or, as Mrs Stevens suggests, by pushing the appellant away or crossing her legs, takes the matter no further ... Indeed it strikes us as a rather unattractive submission given contemporary understanding about how victims of sexual assault may react — and more particularly so where a victim awakes to an assault in progress."
The court similarly dismissed claims that the Crown had overstepped during its closing address in asking jurors to step into the shoes of the victim.
"We are some distance from being persuaded that a jury could not reasonably be sure that the appellant did not have a reasonable belief in consent in these circumstances," Justice Muir said.
Wetere will have his first parole hearing next year.
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.
