David Hall, prosecuting, said Daniel Paul Winterburn, 23, distracted the victim's friend so he could take the girl himself.
He then sexually assaulted her.
In a personal statement, she told the court that because of what Winterburn did to her, her personality changed and she started smoking cannabis.
“I felt like I would do anything to make me me,” she said. “But I realized that it didn't help me. It only made me sleepy.”
She has also stopped eating and is now afraid to be around people, especially men.
“My confidence has taken a huge hit following this incident and investigation,” she said.
Judge Simon Hickey said the incident “must have been extremely harrowing” and that Mr Winterburn's trial, giving evidence and forcing the girl to relive the incident had made the case clearer. He said it made it worse.
Defense solicitor Andrew Semple said Mr Winterburn was of low intelligence and immature. He acted out of character.
Mr Winterburn, of Legion Street, South Milford, denied causing a child to engage in sexual activity but was found guilty by a jury.
The judge said Mr Winterburn must ensure he never commits the crime again.
Mr Winterburn was sentenced to two years in prison, suspended for two years, with the condition that he complete a 43-day rehabilitation program for sex offenders and a 55-day rehabilitation program. He must also carry out 100 hours of unpaid work. He will be registered as a sex offender for 10 years and is prohibited from working with children or vulnerable adults.
The judge also banned Winterburn from having any direct or indirect contact with the girl, from going near the girl's address or other places the girl frequents, and from mentioning the girl on social media. A year-long restraining order was also issued.
Mr Semple said Mr Winterburn had no previous convictions. It has been two years since the sexual incident, and he has not been charged with any crime since then.
IQ tests revealed that he was borderline learning disabled.
He asked the girl if she was “okay” with what he was doing and did not threaten her to not tell anyone what he had done.
Mr Semple said Winterburn was single, had a job, had long-term accommodation and the probation service deemed him to be at low risk of reoffending.
