Adam Johnson's ex-girlfriend tweeted alleged victim
Stacey Founders told the jury in her ex-boyfriend's trial that she had been in Twitter contact with the girl, whom she recognised as one of the people who waited for Johnson after home games.
Miss Flounders said she even wished the teenager a happy birthday on Twitter in 2014.
The testimony came at the end of a morning where Miss Flounders also told the court that she and the former Sunderland star are no longer a couple.
Miss Flounders said the pair would stay friends as she gave evidence in the 28-year-old former Sunderland winger's defence at Bradford Crown Court.
The player has admitted kissing a 15-year-old in his car after grooming the teenager using social media, but he denies that more serious sex acts took place between him and the girl in his Range Rover on January 30 last year.
Miss Flounders entered the witness box in the packed courtroom wearing a black jacket over a light blue top and black jeans.
The 26-year-old was asked by Orlando Pownall QC, defending Johnson, about the future of their relationship.
She replied: "We're just going to remain friends."
Earlier, Mr Pownall asked her why she decided to stay with the player after his arrest.
She replied: "Because he was honest with me and I knew he was telling the truth.
"We'd just had a daughter. I wanted us to be a family."
Asked about messages exchanged with Johnson on the day of the incident with the girl, Miss Flounders admitted she suspected him of being unfaithful at the time.
Mr Pownall asked: "Did you suspect that he was cheating on you?"
She replied: "I did, yes."
When the barrister asked if she had any "hard and fast evidence", she said: "No".
And asked about when Johnson was arrested at their home at 8am, she said: "My head was all over the place. I didn't know what was going on."
She said that after his arrest, her partner said the girl's name and added: "I gave her a couple of shirts."
Miss Flounders said: "I asked how old she was. He said she was 16."
Miss Flounders was handed a tissue by the court clerk and she dabbed away tears after she was asked about "other women".
She had been telling the jury that Johnson made a series of admissions to her after he returned from the police station after his arrest.
Miss Flounders was asked by Mr Pownall if he named the women.
She said: "Just one. He wouldn't tell me the other names."
Asked how many there were, she said: "Quite a few."
Miss Flounders also told the jury that the footballer first told her he was going to plead guilty in about September last year.
Miss Flounders told the jury that Johnson had told her "everything" when he returned home from the police station after his arrest.
Kate Blackwell, prosecuting, then took her through some of the details of the teenager's account of the incident and asked Miss Flounders whether her partner had told her about each.
Miss Blackwell asked her about details including that the pair had kissed with tongues and various messages Johnson had exchanged with the girl.
To virtually all the questions, Miss Flounders agreed that he had not told her, although she said Johnson had mentioned he had asked for a "thank you kiss".
Earlier, Miss Flounders was asked a series of questions about her partner's pubic hair and asked to examine a photograph of his penis.
Mr Pownall said: "Did you see his pubic area fairly regularly?"
After she agreed, the witness said: "He would trim his pubic area but it wasn't that short."
She said he would trim it with scissors.
Miss Flounders added that she had never seen his pubic area shaved.
The teenager involved in the incident has told the jury Johnson was shaved in that area.