A sobbing teenager told Invercargill District Court on Monday that she was raped with an aerosol can by two women because one of them was jealous a former boyfriend fancied her.

Two Invercargill women, Rebecca Louise Elliot, 33, mother, and Sarah Hollings, 19, unemployed, are jointly charged with sexually violating the 16-year-old girl at Invercargill on September 26.

In his opening, crown solicitor Alistair Garland said the victim had been flatting with Hollings and Hollings' former boyfriend, Mark Stenning, for about a month.

The two accused admitted having concocted a plan to get the girl to move out of the flat by pretending to be bisexual. They told police they were trying to scare her, but denied having penetrated her vagina with an aerosol can, Mr Garland said.

The 16-year-old victim, shielded from sight of the two accused, sobbed as she told the court of her ordeal.

The trial, before Judge Phil Moran and a jury, continues Tuesday. - NZPA