The 48-year-old public servant, who cannot be named, is on trial in the ACT Supreme Court in front of Chief Justice Terence Higgins over emails he allegedly sent to the girl during three weeks in 2006.

Jurors were each given a 120-page record of emails sent between the defendant and the alleged victim, who went to school with the defendant's child.

In one message, the man allegedly addressed the girl with, ''Hey sexy!'' and in another he wrote, ''We may even have to do some study together''.

Earlier in the trial, the young woman told the court the man had verbally given her his work email address on a school excursion and she first wrote to him on April 18, 2006.

She said he replied and they subsequently corresponded up to twice a day until May 10. Under cross-examination by the man's barrister, Jack Pappas, the girl said she did not initially want a sexual relationship with the man.

''I got to know him a bit better before I decided that,'' she told the court.

Yesterday, the jury was shown a video of a police interview in which the man told investigators he felt stupid.

''I'm very angry with myself,'' he told police in May 2006.

''I should have put a stop to it. They're not appropriate, I know that now.''

He described the email exchange as a ''stupid, flirtatious thing'' and vehemently denied planning to have sex with the girl, saying, ''Not at 15, no way.''

The trial continues today.

For more on this story, see today's Canberra Times.