Married teacher Andrew Welsh, from Atherton, near Wigan, had been having a relationship with the woman’s 16-year-old daughter, which she discovered when she arrived home early July.
Mr Welsh, 36, admitted his sex offences and has been jailed. A court heard how he had sent the girl texts including: “Have you heard about my maths lesson? We’re going to find out if 36 goes into 16.”
When the mother came home unexpectedly, she noticed a pair of man’s boots by the side of her daughter’s bed, and also that she had ‘ruffled hair and smudged lipstick.’
Prosecutor Geoff Whelan said: “She saw movement which seemed to match the material of the suit jacket her daughter was holding. She asked the girl, ‘what are you doing? Who is here?’
“The girl replied, ‘Me Welsh’. Her mother ordered the defendant to get out from under the bed and recognised him from the school.
“She called her husband, the school and the police. She also spoke to the head who told him to return. He was arrested at the school.”
Following his arrest, during interviews, Mr Welsh claimed that he believed the girl had finished school and that what he was doing ‘was not illegal’.
Defence Nicola Gatto said: “Quite what possessed him to embark on this course of conduct is quite unclear.
“I am not saying that this young girl led him on, but this was a young girl who had attained the age of consent and she makes no bones about the fact that she found Andrew Welsh attractive.”
Mr Welsh admitted to the charges – six counts of sexual activity while in a position of trust – and was given a two year suspended sentence of 14-months, community service and ordered sign the sex offenders register for 10 years.