Stacy walked out of the court sitting on Friday when sexually intimating Whatsapp messages between her partner and the under age girl were read out loud in court by the prosecuting attorney.
The accuser, the under age girl who the police have refused to reveal her identity testified against the footballer in a recorded video interview and says she was ready for what could happen between her and the footballer although it was wrong.
Asked how she felt, the girl said: 'As much as I expected it to happen, I was a bit shocked it had. I sort of knew I had done something wrong.'
She added: 'It wasn't that I didn't want it or anything. I just knew it was wrong.'
'I got a message from Sunderland player Adam Johnson who I'd idolised for quite a while.'
The girl said that, after exchanging messages, she first met-up with Johnson on January 17 last year when he signed two Sunderland shirts for her.
She then explained how the player continued to message her, talking about getting a 'thank you kiss'.
'I was well up for it. It was a surreal type of thing,' she told the police officer. 'I met up with him again. I gave him his thank you kiss and more,' she said.
The girl described how Johnson exchanged WhatsApp messages with her after their first meeting, saying 'you owe me for this' and 'am I going to get a thank you kiss?'.
The teenager said that at the second meeting, in the player's Range Rover, Johnson said to her: 'I've come for my thank you kiss.'
She said that she eventually told him 'go on then', and they began kissing.
The girl said: 'I was kissing him for quite a while.'
'He undid the button on my trousers. It took him a while to do that,' she said. 'He got his hand down my trousers. He started to put his hands in my knickers.'
The girl then described to the officer further sexual activity between the pair.
Later in the interview, the police officer asked the girl what Johnson knew about her.
She replied that the player knew how old she was, what school year she was in and where she sat at Sunderland matches. She said Johnson also knew her date of birth.
She said: 'He asked me when I was 16.'
Johnson has already admitted one count of sexual activity with a child and another of meeting a child following sexual grooming.
The one-time England midfielder is accused of abusing 'his revered position in society' when he had sexual contact with the teenager 'in a way that he knew was both morally and legally wrong'.