Johnson has pleaded not guilty to two counts of sexual activity with the 15-year-old, while admitting to one count of grooming and one count of kissing the girl.
The teenager appeared in Bradford Crown Court via video link to give evidence on the third day of the trial and slammed the 28-year-old for his actions.
"He made me out to be a liar and told everyone he was innocent. He let people cheer him on for matches and call me all the names under the sun," the alleged victim said.
"He knows for a fact that he did that to me. He lied about the others (the grooming a less serious sexual activity charges) for a year and now he has admitted it."