A court heard that Craig Hill “exploited” one of his pupils, who had a “teenage crush” on him, while he was a maths teacher at Hall Park Academy in Eastwood, Nottinghamshire.
The 46-year-old was jailed for 32 months at Nottingham Crown Court on Friday after the girl came forward several years later to report him to police.
He pleaded guilty to two counts of sexual activity with a child and one count of causing or inciting a child to engage in sexual activity on the first day of his trial in August.
Prosecuting barrister Dawn Pritchard said Hill, of Mornington Crescent in Nuthall, Nottinghamshire, touched the girl under the table and in a school cupboard at the back of the classroom on “a number of occasions”.
She went on to say that the victim had previously said she was “in love” with him and had touched him sexually because she “wanted to impress him”.
Ms Pritchard added that Hill once unbuttoned his shirt in the cupboard and the girl was “shocked at how hairy his chest was”.
In a statement read to the court by Ms Pritchard, the victim wrote that the offenses had affected “every aspect” of her life.
“I feel like I’ve lost so much precious time and my childhood,” she said, “I can’t remember school because every memory is tainted for me – I was a child and I was raised by this man.
“I have to keep reminding myself that I was a kid. My only responsibility was to be a kid and nothing I could do would change the outcome.
“I’m worried and wary of bumping into him, and I always will,” she added.
Sentencing, Judge Stuart Rafferty QC said: ‘You were in a position of responsibility towards this girl. It probably became clear to you very early on that she had some kind of feeling for you – some sort of teenage crush – sometimes students mold themselves to those who teach them.
“All you had to do was politely but firmly show her the door. The fact that you didn’t speak speaks volumes. It is abundantly clear that you did not discourage her in what she felt – on the contrary, you exploited it.
“She, the love child who was without previous sexual experience, could not begin to understand the ramifications of what was happening and the effect.
“There’s a lingering effect on that child, who she still is — still the child trapped in an adult’s body because of what happened to you.
“I believe you now feel remorse, but whether it is remorse for others or for yourself is less easy to determine.”
Hill stood in the dock wearing a navy blue suit and did not react as the verdict was read.