A 66-year-old man asked an undercover police officer to send him pictures of her breasts, believing her to be a teenage girl, a court heard.
Timothy Dowd met "Chantelle", an officer posing as a 13-year-old girl in care, in a chatroom, a court heard.
Leeds Crown Court was told that Mr Dowd, of Harrogate, also asked the officer to engage in phone sex with him.
He denies attempting to incite a child to engage in sexual activity.
He also denies attempting to engage in sexual conversations with a child for the purpose of sexual gratification.
'Thought girl was older'
The offences are alleged to have taken place in mid-January 2018.
Jurors were told that Mr Dowd, of Chatsworth Grove, did not dispute the nature of the conversations but believed he was talking to a girl aged 16 or over.
Rupert Doswell, prosecuting, said that although the undercover officer declared herself to be 16 when signing up for the Lycos chatroom to comply with the site's rules, she quickly told Mr Dowd she was 13 after being invited to a private chat.
The court heard Mr Dowd replied her age "was not a problem" for him.
He also exchanged phone numbers with "Chantelle", and used WhatsApp to make a call, requesting she sexually touch herself while he pleasured himself, the jury was told.
According to the prosecution, Mr Dowd later became suspicious that he was the subject of an undercover sting.
He was arrested a few days later at a property in Leeds, where his phone was seized.
The trial continues.