But first their relationship will have to weather a storm - his ACT Supreme Court trial for having sexual intercourse with a child.

The 19-year-old has pleaded not guilty to five counts of having sexual intercourse with the girl when she was 14 and he was 17 and 18.

She became pregnant but miscarried, and the Crown alleges her boyfriend was the father.

Police became involved after hospital staff, bound by mandatory reporting obligations, contacted authorities.

Under territory law, as in most other jurisdictions, a child younger than 16 cannot consent to sexual intercourse.

There is a legal defence available if the age gap between the two is no more than two years - a provision designed to protect young lovers from prosecution.

In this case, however, the three-years-and-seven-months age difference falls outside that window.

By the time of the trial next year the girl will be 16, but if the young man is found guilty and a conviction is recorded, he will be placed on the national child sex offender's register.

Neither teen can be named because she is a child, now 15, and he was underage when some of the alleged offences occurred.

The pair was able to resume seeing each other again earlier this year, after a year apart, when a judge varied the accused's bail to allow them supervised contact under strict conditions, including that they not have intercourse.

''Before [he] was charged, we had spoken about the possibility of getting married, when I was old enough to,'' she told the defence lawyers.

''I still want to get married to [him], when I can.

''I love him very much, and all I want is for us to be able to be together.''

She has refused to provide a statement to police or prosecutors.

''This is because I am in love with him, and I do not wish him to be prosecuted for these alleged offences,'' she said.

Court documents also show the girl's mother was aware the pair were in a relationship, and approved of her daughter's boyfriend.

The man's solicitor, Ben Aulich, wants the Director of Public Prosecutions to drop the case, arguing the prosecution is not in the public interest. ''This law is about the protection of children and very important,'' he said.

''However, in this case, a prosecution and conviction for this young man will clearly lead to an unjust outcome and is not in the public interest.

''This case is about a loving and caring relationship between two young people. This is not the evil the legislation was designed to sanction.''

Acting DPP John Lundy said it would be inappropriate for the director's office to comment because the case is due to go before a jury.

But before proceeding with any prosecution, the DPP is required to consider a number of factors, including whether it is in the public interest to pursue the matter.

At the bail hearing earlier this year, Acting Justice John Nield agreed to allow them contact, under parental supervision, but banned them from having sexual intercourse, being in a bedroom together or spending nights in each other's company.

And the judge questioned whether the DPP should proceed with a prosecution, given the accused man could be branded a sex offender.

The Crown alleges the pair met in September 2010, when she was 13 and he was 17.

The five allegations against him date from between December 2010 and July 2011, when she was 14 and he was 17 or 18. The prosecution alleges the young man made a statement to police admitting to having an ongoing sexual relationship with the girl.

The alleged offences came to light when, in July 2011, the teen girl went to Canberra Hospital after a miscarriage in the first trimester of her pregnancy.

The hospital contacted police and it is alleged the man was identified as the father of the unborn child.

The case is due back in court this week for a pre-trial hearing.