The 21-year-old man, who cannot be named, pleaded guilty in the Warrnambool County Court yesterday to sexual penetration of a child aged under 16 years.

He was sentenced to 15 months’ imprisonment with six months to serve. The man was also placed on the sex offenders’ register for 15 years.

The second cousins grew up together in a small town and on Australia Day this year were with friends listening to music, watching television and drinking beer, spirits and shots, including playing drinking games.

The man and the victim also sent each other a series of text messages with sexual undertones.

About 11pm the girl went to bed, after which the man entered her bedroom, got into the bed and had sex with her.

In the coming days the victim’s mother noticed the girl was crying and distant. Late on February 7 she received a text message from her daughter explaining what had happened.

The girl then sent the offender a Facebook message telling him she cried herself to sleep every night, that he had taken advantage of her and asked him to never contact her again. The man immediately replied saying he was very sorry. He asked for forgiveness and explained he was very drunk.

He later told police he and the girl were so drunk they could hardly stand up.

Asked what the victim was doing when he was having sex with her, the man relied: “nothing really, she was not saying anything”.

In a victim impact statement, the girl’s mother said her daughter now suffered depression, had repeated nightmares and had tried to commit suicide. She and her husband felt they had lost their beautiful daughter and worried she would not be alive when they woke up.

“It’s nightmare he has inflicted on her for the rest of her life,” the mother said.