A music teacher explaining strumming told a schoolgirl to think of the hand technique as a gesture to make to boys.
Keith Jenner had been teaching the Green Day song "Wake Me Up When September Ends" the to girl, who was in sixth year studying Advanced Higher guitar.
The former pupil, now studying to be a music teacher herself, said her background had been in classical and Spanish guitar - which involved plucking - and Jenner had been teaching her to strum so she could also play pop.
She gave evidence from behind a screen at Falkirk Sheriff Court, where Jenner, 56, is on trial accused of sexually assaulting and making sexual remarks to pupils at a series of secondary schools across Stirlingshire and one in the geographical area of West Lothian where he was a peripatetic teacher.
She told jurors he showed her some strumming, and then pointed at two boys through a practice room window at her Central Scotland high school and told her, "Imagine giving that to those two out there."
She said: "It wasn't appropriate. The two boys were obviously younger that I was. It didn't sit correctly."
She reported the matter, which was taken up with Jenner, who later apologised.
Principal teacher Annabel Stewart said the suggestion had been that the girl should have "thought about doing the gesture" to the boys.
Miss Stewart, 41, head of expressive arts, told jurors: "It's a strumming pattern so it obviously resembles a sex act."
Another witness, then 15, told the court that Jenner had shown him and another boy a video of a woman playing the bass guitar while wearing "a revealing, low-cut top".
But the boy, who said Jenner would touch his knee and rub his shoulder during lessons, agreed with Jenner's counsel, Mark Stewart, QC, that the top was "the sort of thing you'd see in the street on a summer's day".
Jenner, of Bonnybridge, Stirlingshire, denies sexually assaulting four schoolgirls aged 15 and 16, and four schoolboys, aged 13 to 15, by touching them on the body; directing "sexual verbal communications" at teenage pupils; and showing boys a video of "a partially-clothed female".
The incidents are said to have taken place over a period of more than three years ending January 2020, at four high schools in Stirlingshire and one in the geographical area of West Lothian.
The trial, before Sheriff Derek Hamilton and jury, continues.
