A student teacher carried out a sex act with a 14-year-old pupil after grooming her on the website Facebook.
Craig Beeden, 22, of Topcliffe Avenue, Norwich, lured his "favourite" pupil on the social networking site and swapped numbers, Cambridge Crown Court heard.
Beeden, who taught at a school in Cambridgeshire, admitted two counts of sexual activity with a child.
He was made the subject of a three-year supervision order and banned from working with children for five years.
After exchanging telephone numbers the pair secretly held intimate meetings in Beeden's office, the court heard.
Sally Hickling, prosecuting, said: "They met between lessons in his office and would kiss. They were careful not to be caught."
Their relationship only ended when the youngster's father found explicit text messages on his daughter's mobile phone, sent by Beeden.
Beeden, a student of De Montford University in Leicester, was on a work placement at the school when the incident occurred last year.
Passing sentence Judge Gareth Hawkesworth said: "This did not come about because of manipulative seduction - it came about because you were a teacher."
Beeden was also ordered to attend a sex offenders' programme for 200 hours and was placed on the sex offenders' register.
A Cambridgeshire County Council spokesman said: "We feel that the courts have taken appropriate action."