The alleged victim said she initially did not believe her drink had been spiked.
She told the court: “I remember vividly defending Mr Nath, saying ‘There is no way he could do that’.
“I remember sending him a message saying ‘I’m sorry, I don’t know what’s happening’. Because I felt it was my fault.
“I didn’t want him in trouble, I didn’t believe it.”
The woman said she met Nath while going through a divorce and “a bit of turmoil in my family”, adding she had had a “very big falling out with my father”.
Discussing her first meeting with Nath, she told the court: “He kindly invited me for a drink. He seemed genuinely concerned about my welfare, where I was going to be living.”
At their first meeting, Nath gave the woman and her friend a bottle of Jo Malone perfume, saying “it is what his mother likes”.
The woman said that Nath “always paid” for their lunches, adding “he was very generous” and that she did not work.
Discussing their relationship, the woman told the court: “He came across as he cared for me and it was nice. I never thought he would have made a physical move on me so I felt safe with him.
“He never spoke of anything of a sexual nature.”
Asked by the defence if she had told Nath about her boyfriend, the woman told the court: “He was aware. I did not speak about him often, but he was aware.”
Discussing her interactions with Nath prior to January 15 2024, the woman said: “We always air kissed and it was never inappropriate.”
Nath denies attempting to administer a substance with intent and possession of a Class B drug.
The trial continues.