He said he told his club "everything" after his arrest, including that he "kissed [the girl] with tongues and felt aroused".
Johnson was suspended by the club on March 2 after his arrest, but reinstated on March 18 and played up until February 6, scoring in his last game against Liverpool and throwing his shirt into the crowd.
Referring to his shirt throwing, Miss Blackwell asked: "Is that because you knew the game was up?"
Johnson replied: "The game with Liverpool?"
Miss Blackwell said: "The game you have been playing with these courts."
Johnson replied: "I knew there was a possibility it could happen, yes."
Miss Blackwell asked Johnson what he would think of someone who avoided doing the right thing because doing so would lose them money. He said: "It wouldn't be good."
The prosecutor said Johnson knew he would have to sign the sex offender's register once he had pleaded guilty, which could bring an end to his career.
She suggested that the footballer might have delayed admitting his guilt in the hope that the girl would lose her "courage and composure to give evidence" and lead to the case "crumbling away", which he denied.
Miss Blackwell said the girl, who has been described as a "massive, massive Sunderland fan", received abuse at the club following Johnson's arrest.
She said: "And each week that you played for the football club and refused to acknowledge your guilt was another week perpetuating the excruciating pain for the girl, wasn't it?
"She endured a year of being called a liar and a slag while you encouraged your fans to cheer you on."
Johnson agreed but said: "I was doing my job."
He said he could not control his fans or what other people said on his behalf.
Johnson was also questioned about his meeting with the girl, when she alleges she performed oral sex on him.
He said: "Before the meeting I was considering doing other sexual things but nothing else happened, I can't stress that enough."
The teenager told police that Johnson's groin area was shaved of pubic hair.
Under cross-examination today, he denied he had even been clean shaven in that part of his body.
Earlier today, Johnson admitted that he gave the 15-year-old girl his phone number because he wanted a sexual relationship with her.
Johnson's own QC, Orlando Pownall, asked him: "Did you give the girl your number because you wanted to have a sexual relationship with her?" Johnson replied: "Yeah."
The 28-year-old was also questioned over his police interview and admitted he'd lied to detectives.
He said he told them his kiss with the girl wasn't passionate but now accepts it was.
Johnson also told officers he had no feelings for the girl, but said today that he was "trying to play it down".
He said his world was "turned upside down" when he was arrested and he "panicked" during his police interview.
Johnson admits grooming and kissing the youngster but denies more serious sex acts took place during a meeting with her in his car early last year.
The girl says she performed oral sex on the player in his car and he put his hand down her trousers.
Today, Johnson told the court that, when confronted with her allegations by police, he"felt like someone was making her say these things for the benefit of herself".
Asked directly by his lawyer whether they engaged in oral sex, Johnson replied: "No".
The England winger yesterday told the court he enjoyed kissing the girl and wanted to touch her sexually.
He described his messages to the girl as "flirty" and "inappropriate" and said he was "ashamed" about sending them.
When asked how he felt now, he said: "Embarrassed. Awful. I shouldn't have ever done it."
He added that the messages were his fault and that he "should have known better".
The trial has heard that Johnson met the girl twice in his black Range Rover after exchanging telephone numbers and messaging each other over a number of weeks.
The footballer signed Sunderland shirts during the first meeting in January last year and has admitted kissing the teenager during the second meeting.
Messages between the pair discussed meeting for a second time so the girl could give Johnson a "thank you kiss" for the shirts.
They met in a car park on January 30 where the girl says she performed oral sex on the footballer. Johnson denies to oral sex allegation. He says they kissed before he dropped her at a shop "to buy some sweets or something".
The trial continues.
