No matter how sophisticated, mature or sensible a 16-year-old girl feels herself to be, it can never be right that an adult who has responsibility for her in a school, college or any other such establishment is allowed to begin a relationship with her.

Laws are in place to prevent this happening for very good reason. Adults in positions of power and trust must never, ever abuse that position and trust, and they know full well why.

Now Jonathan Firth is finding that out to his cost, after the teacher at a Bradford high school was jailed for the relationship he began with a student supposedly under his care and supervision.

There is no excuse for what Firth did. He may well have been "flattered" by the attention of a girl more than half his age, but warning bells should have sounded sufficiently loudly within him to ensure that it went not a step further.

Instead, he gave in to his weakness and embarked upon a sexual relationship with the 16-year-old, who was a virgin at the time of the offence.

Parents put their trust in schools to look after their children, and in no mother or father's worst nightmare would the idea of a teacher bedding their daughter be even entertained.

Firth has betrayed the trust of the girl, her parents, and his employers. That he even denied the full extent of their relationship until the girl was called to court to give evidence shows just how untrustworthy he is around young people.

It is unlikely - and undesirable - that he will ever be in a position of trust where children are concerned ever again.