A 25-year-old Corsham man who started having sex with a girl when she was 14 has been jailed for two years.
Lee Collingwood befriended the youngster at a bus stop when he offered to help her when she was being bullied by school mates.
But as their friendship developed the couple started having sex.
And he also made a film on his mobile phone of the child carrying out a sex act which he kept on his computer along with other indecent images of the girl.
Colin Meeke, prosecuting, told Swindon Crown Court on Friday that they fmet in September 2012 at a Chippenham bus stop.
He said Collingwood offered to wait with her as she was being teased by boys from school and, as they parted, they exchanged phone numbers.
"They started contacting each other on a daily basis. She, it is quite clear, very quickly became fond of him. She trusted him," he said.
The girl has a number of personal problems which he helped her with and it was clear her parents knew of the friendship, the court was told.
He was fully aware if her age and early last year, a couple of months before her 15th birthday, they had sex in his flat despite having discussed the legal consequences.
Mr Meeke said the couple had sex a number of times until Collingwood's female lodger came home unexpectedly and heard the couple in his bedroom.
He said: "She challenged both the defendant and the girl and there followed then an exchange of emails and other messages between the lodger and the complainant trying to explain to her the way she had been used and abused by the defendant.
"It was the lodger who reported the matter to the police."
Mr Meeke said the teenager did not see herself as a victim and said she still loved the defendant.
Collingwood, of The Laggar, Corsham, was arrested and made a full admission to the police about what had happened.
He pleaded guilty to two counts of sexual activity with a child, taking, making and possessing indecent photographs of a child.
Mark Ruffell, defending, said what his client had done was not predatory but an act of stupidity.
He said that they had been friends for a number of months before it became sexual and many people, including her family, knew they saw each other.
Although Collingwood accepted making the movie of the girl, he said the other images she had sent him or placed online herself and had asked him to try to remove them for her.
As well as holding down jobs at Argos and Travelodge, which he had left as a result of the conviction, he was also active in the local charity science-fiction group.
He would go along to events free of charge dressed as characters from Star Wars, Doctor Who, or other sci-fi shows, so visitors could have their photo taken with him.
Jailing Collingwood, Judge Tim Mousley QC said: "I take very much into account the age difference between the two of you, ten years or so in terms of mathematics.
"I take into account the affection she undoubtedly had for you, I also take into account to a limited extent assessment of her vulnerability.
"Looking at her vulnerability one has to look at the often quoted need to protect certain people such as her from herself."
He imposed a two-year jail term and told him he must register as a sex offender for ten years and also be subject to a sexual offences prevention order, restricting his liberty, for that period.