A 15-year-old girl who was allegedly gang raped at the first proper party she had attended pleaded for her attackers to stop but they laughed in her face, a court has heard.

Four men are on trial accused of participating in the sustained group sexual assault of the teen at a house party in Hazelbrook, in the Blue Mountains, in October 2012.

Aaron Jensen, 23, Christian Dickens, 22, JR and SK, both 21, have pleaded not guilty to multiple offences and their trial started in Sydney's Downing Centre District Court on Thursday.

In her opening address, Crown prosecutor Belinda Baker told the jury that the girl consumed large amounts of wine at the party and was noticed stumbling and slurring her words.

View More