A Newark man on trial for the murder of a teenager was accused on Friday of doing nothing to save her.
James Morton, 24, of Pierson Street, denies the murder of Hannah Pearson, 16, on July 24 last year.
He has told the court her death was an accident.
Prosecutor Mr Michael Evans QC told Morton at the end of a three-hour cross-examination: "This was not an accident. This is about you strangling a woman. This is your fantasy come true.
"By the time you killed her, you had her life in your hands. A 16-year-old girl who you did nothing to save.
"Your only interest after you killed her was yourself."
Mr Evans asked Morton why he had done nothing to save Hannah and had not administered chest compressions or mouth-to-mouth.
"You didn't try to save her, you let her die," said Mr Evans.
"Not true," replied Morton.
Morton was asked about a first aid certificate he was said to have received from the Prince's Trust in 2011.
He said he had not received a certificate and did not complete the course.
Morton said he ran downstairs to get help for Hannah from someone more capable than himself.
He called the police and waited for them in the garden.
Nottingham Crown Court was told that Morton had previously put his hand on the necks of two other women during sex. Both had stopped him.
Mr Evans asked him if the desire to strangle was escalating by the time he met Hannah.
"Not an escalating desire, no," replied Morton.
The court had earlier heard that Morton had met friends in Lincoln during the day of July 23.
In the evening one of them, Jed Hope, was joined by his girlfriend Hannah Pearson.
Hannah and Mr Hope were asked by Morton if they wanted to go back to his parents' home because they were away.
Mr Hope said he had not got the money for the train fare but Hannah decided to go.
Once back in Newark, Morton said he and Hannah had some drinks in the garden.
Morton said she was drunk and he had helped her upstairs where she laid on his bed fully clothed.
He covered her with a duvet and then stripped down to his underwear and lay beside her.
He said he had no intention of having sex with her but she had kissed him.
Morton told the court she had allowed him to help remove her clothing.
She laid on her back under the duvet and he had sat across her.
He said he had put his left hand around her throat.
She asked him what he was doing and he said he had told her to say if she did not like it and for him to stop.
He then put his right hand on the top of his left and applied sightly more pressure.
At one point during the cross-examination Morton said: "Do you realise how disgusted I am in myself?.
"I have flashbacks. I did not sleep or eat in prison for two weeks after it happened.
"There is nothing I can say or do that can ever change what happened."
The trial continues.