A teacher who kissed a former student in front of pupils, parents and colleagues has been found guilty of unacceptable professional conduct by England's General Teaching Council.
Irene Evans started dating the former student after he left Manshead school, a Church of England comprehensive, in Caddington, Bedfordshire.
She disobeyed the headteacher's instructions not to take him to the school's drama performance evening.
The head of department was found to have brought the school into disrepute after attending a private party given by one of her boyfriend's friends, who was still at Manshead.
Liz Carter, GTC committee chair, said Mrs Evans's action had inevitably led to gossip.
"She gave no thought to the difficulties and embarrassment that this caused her colleagues, particularly the headteacher, in having to deal with the inevitable comments and questions from other students.
"By her own admission, she brought the school's reputation into disrepute."
But the GTC offered no comment on the relationship as it began after the boy left school. Mrs Evans joined the school in September 1999 and left in August 2003. The hearing was not told whether the relationship still exists.
The GTC heard she disobeyed an instruction given in February 2003 by the school's head by taking the pupil to an AS and A-level drama performance evening in May 2003 without warning.
Ms Carter said: "As she has now accepted, her conduct fell short of the standards expected of a registered teacher and her behaviour involved a breach of the standards of propriety expected of the profession."
The committee decided Mrs Evans's actions had not affected students'
examination results after hearing that she and the boy left and re-entered the hall during the performance.
An allegation that Mrs Evans had exercised poor judgement in dealing with staff and pupils was not proven.
The GTC found that Mrs Evans had not shown insensitivity towards staff and had not failed to establish positive working relationships with colleagues.
Ms Carter said: "Mrs Evans's behaviour was unacceptable and it must not happen again. However, Mrs Evans had accepted her wrongdoing and had apologised.
"She had previous good history. The committee had before it a number of references and testimonials, including the headteachers at her previous and current schools.
"They spoke highly of her abilities as a teacher and there has been no repetition of this behaviour."
Mrs Evans is now teaching at another school and the reprimand will be noted on her registration.
PETER WILBY 19