A therapist from North Somerset has admitted showing a client a picture of his penis on his mobile phone because he thought she was "broad-minded".
Mr Midda said he was "stunned" when police arrested him
Julian Midda of Eastcliffe, Portishead is alleged to have inappropriately touched the pensioner twice while treating her at home in south Wales.
Mr Midda denies two counts of sexual assault on 24 April 2006.
He admitted showing the picture was inappropriate, but added: "She seemed quite amused by it."
He claimed to have been showing her pictures of a family holiday to Disneyland Paris when she saw the photo over his shoulder.
Answering questions from defence barrister Stephen Mooney at Cardiff Crown Court, Mr Midda said: "I said 'I shouldn't show you that, it's a bit of a naughty one.' "She said: 'Who's that then?' and I said: 'It's me'."
Mr Midda told the jury of four men and eight women the woman asked to see the picture.
'Stunned at arrest'
He said he believed her to have a relaxed attitude as her husband had previously shown him pornographic videos on his own phone.
"There didn't seem much harm in it. It was pretty naff," he said.
Mr Midda said as he left the couple's home after the treatment finished, the woman asked for a cuddle and he shook her husband's hand.
He said he was stunned when police arrived at his family home in Nailsea three days later to arrest him and told him of the allegations made against him.
The trial continues.