Gayle Newland, 25, won the woman's trust using a fake online persona, and the pair struck up a two-year relationship, jurors were told.
The alleged victim told Chester Crown Court she had believed she was having sex with a man.
Ms Newland, of Willaston, Cheshire, denies five counts of sexual assault.
The pair met in 2011 after Newland set up a bogus Facebook account under the name Kye Fortune, the court was told.
"Kye" had told her he was in hospital, she said, and was not well enough to see her after he was treated for a car accident and a brain tumour.
But the pair spoke frequently on the phone, the court heard, and eventually arranged to meet for sex at a Chester hotel on the condition the woman wear a blindfold.
She said Kye was waiting in the bathroom when she entered the room and bed was covered with rose petals and Hello Kitty bears.
The pair then had sex, the court heard.
During interviews, the woman told police Kye asked her to wear a blindfold because he was "anxious about the way he looked" and "could not walk properly" due to nerve and muscle damage.
Eventually Kye visited the woman's flat and the truth was revealed, the court heard.
Describing the pair's final sexual encounter, she said she had been shocked when she removed the blindfold and saw Ms Newland instead of Kye.
"Gayle was just standing there. I just couldn't believe it," she said.
She told the interviewing officer: "I couldn't believe that person would want to do something like this to me... these last two years had fabricated this world around me.
"He - Gayle - pulled the wool over my eyes."
The trial continues.
A woman tricked her friend into having sex with her by posing as a man and persuading her to wear a blindfold in the bedroom, a court has heard.