A boy and girl who laughed while taking photos of a school friend while she was drunk and semi-naked told a jury they went too far and no longer thought it funny.

The 15-year-old boy said he was disgusted with himself and the girl, aged 14, said what happened to the unconscious teenager was horrible.

Both are on trial at Bradford Crown Court with a girl aged 15. All three deny sexually assaulting a 13-year-old girl in a field in Queensbury on December 22, 2011.

The 15-year-old girl pleads not guilty to taking or making indecent photos of her and distributing some of them by sending them to another boy’s phone.

The boy and the younger girl deny taking indecent photos of the girl.

Images of the teenager, taken by the two 15-year-olds, have been shown in court. Her clothing is stripped off, she is covered with mud and grass and, the prosecution say, she is being sexually abused.

The three defendants, who cannot be named, are alleged to have carried out a humiliating sexual assault on the girl while she was “out of it” after downing most of a bottle of vodka.

All three admit taking photos of the girl for a laugh but say there was nothing sexual about them.

The boy told the court yesterday he and the others took photos of the girl because of the state she was in. She might later find the pictures funny.

“I knew it had gone too far when the police came along,” he said.

He put the photos into a file on his phone called “Lasses”. The boy said he did not touch the comatose girl or remove any of her clothing.

The 14-year-old girl said the drunken teenager took down her own trousers and knickers because she needed the toilet. Her top was ripped as she rolled about on the floor. She had seen her drunk before and did not think it serious.

The girl said she took photos of the girl’s face but later deleted them.

“I was laughing a bit but then it became a bit more serious because she wasn’t responding to anything that was happening,” she said.

The girl added: “It was horrible what happened to her.”

The trial continues.