The woman said during the journey King slipped his hand under her sweatshirt and underpants.
"I couldn't believe what was happening, I felt trapped. I was just hoping the hospital would appear soon," she said.
After arriving at hospital, she said King lingered near her before grasping her shoulder and saying: "I'll be in touch."
The woman said she was then "bombarded" by "very intimate" text messages and phone calls from King.
However, the woman said she "foolishly" replied with messages of her own, which one read: "I want you so much. I'm yours forever. Your sweet pea."
"Yes, I was replying in the language he was using," the woman said while under cross-examination from King's lawyer, Bill Calver, yesterday morning.
"Why didn't you immediately protest to the [ambulance] driver?" Mr Calver asked the woman, referring to the alleged incident.
"I didn't know if it was just Chris [King] involved," the woman replied. "I didn't know if the other ambulance officer was in on it."
Mr Calver retorted: "You say this man did this to you but you willing engaged in a text relationship with this man?"
He suggested to the married woman: "In a small town, had you in fact embarked upon an affair it would have been problematic, wouldn't it?"
The woman said the text relationship was "just words" and she had no intent to meet King. She said she was "flattered" by his attention, while the two engaged in text and phone conversations, including a more than 24-minute call on one occasion.
She added she felt embarrassed about a text relationship from one end of a device and "didn't feel like herself".
"You felt guilty about how you behaved in an uncharacteristic way," Mr Calver said, suggesting the woman had fabricated the entire incident in the back of the ambulance.
The woman said she felt "guilty" about replying to King's messages but "hadn't made up the allegations".
Two days after the incident the woman first spoke of the alleged assault to her psychiatrist, who she was consulting for depression, but it was more than a month before she told her Waipukurau GP and informed police.
When she reported the alleged incident to a detective she initially declined to inform him of the text message conversations she had with King.
The second ambulance officer, Vaughan Thompson, who was with King during the June 23 job also gave evidence yesterday.
He said upon arrival at the woman's house, the tearful lady informed the medics she was in a "dark place" and mentioned potential self-harm.
Mr Thompson said while driving to the hospital his view into the rear of the ambulance from the drivers seat included the back of the stretcher, the patient (from the knees down) and the back of people's heads.
He said upon arriving at the hospital the woman appeared in less pain, while the rapport between King and the patient "seemed good".
Throughout the first week of the trail allegations relating to a then 15-year-old girl, who was a patient of King's on July 24, 2013 were also heard.
The trial before Judge Geoff Rea continues on Monday.
