A teaching assistant broke down in tears as she confessed to sending a schoolboy sexual photographs of herself for a year and performing sex acts as he watched online.
Elaine McKay, 58, worked at the Clacton Coastal Academy when the offences happened, Chelmsford Crown Court heard.
Ms McKay, of Clacton, denies having sex with the 15-year-old boy and inciting a child to engage in sexual activity.
She told the jury: “I’ve never had sex with him.”
Ms Mckay is accused of starting a sexual relationship with the teenager while working at the 1,700-pupil school.
She wept as she admitted sending explicit pictures to the schoolboy, who cannot be named for legal reasons, for about a year.
She confessed to performing “graphic sexual acts” on herself as he watched on Skype.
Maria Dineen, defending, said: “You accept that there were messages and pictures sent by you and activity on Skype that was of a sexual nature.”
McKay, a mother-of-two and grandmother-of-two, replied through tears: “Yes. Sorry, yes.”
Taking a sip of water to compose herself, the teaching assistant – who has been suspended from her job – insisted it was the schoolboy who started it by asking for a picture of her.
She said he sent her a picture of his privates and she responded by sending him images.
She told jurors: “He kept pestering and asking me ‘please, just one picture, just one picture, even if it’s just a pair of knickers’.”
Ms McKay, of Banister Close, said the first explicit picture she sent him was a “silly” picture of her shower which had her underwear hanging in the background.
Asked why she sent the pictures, Ms McKay said: “I have no idea whatsoever. This is my regret. I don’t know, I don’t know the reason.”
The court previously heard how the relationship began after Ms McKay visited the pupil’s home to drop off a cake.
The schoolboy claims the pair had sex afterwards.
His relatives were not in and the teenager said he went and had a shower. He claims that on his return Ms McKay was waiting in his bedroom, ripped off his towel and had sex with him.
But she vehemently denied having sex with the schoolboy and insisted she had never been alone in a room with him.
The trial continues.