A friend of murdered Lucy McHugh claimed the 13-year-old schoolgirl said she loved her alleged killer and he had taken her virginity, a court has heard.
Carer Stephen Nicholson, 25, is accused of stabbing her in the neck and upper body near Southampton Sports Centre in July last year.
The trial was told Nicholson was a lodger in the house Lucy shared with her mother Stacey White and her stepfather Richard Elmes.
And the defendant exploited the "vulnerable" teenager for more than a year, it was alleged.
Lucy's friend, who cannot be named for legal reasons, told Winchester Crown Court that Lucy confided in her that Nicholson was becoming violent towards her, claiming he slapped her and tried to force his way into her bedroom.
She said Lucy told her Nicholson was her boyfriend in October 2017, when she was aged 12.
The girl said in a police interview shown to the court: "She started telling me she was with a 24/23-year-old called Stephen.
"I asked if them two had done anything because I was really worried.
"She told me he took her virginity but when she told me she looked uncomfortable and scared."
The girl said she told her mother, who contacted Ms White, who then rejected the claims as "fantasies" and said social services had already looked into the allegations.
Nicholson became possessive over another boyfriend Lucy had, adding the defendant said "he would try to bash his head in", the court heard.
She said she urged Lucy to leave the house and live with her grandparents.
"She kept on saying she wanted to but she couldn't. She kept telling me not to worry and she would sort it but I kept worrying about her because she kept not looking right and not acting like she used to," the friend said.
The defendant is charged with Lucy's murder as well as three counts of rape when she was 12.
He also faces two charges of sexual activity with a child on multiple occasions when she was 13.
He is also charged with sexual activity with a child in relation to another girl aged 14.
Nicholson, of no fixed address, denies the charges and the trial continues.