Joshua Bevan told a Ballarat jury on Friday he was living with his friend, Morse, and was at the Redan house on the night of July 15, 2017.

Police have alleged Morse pushed the barrel of a gun into the 25-year-old woman's rib cage and led her into the bathroom where he raped her.

He is accused of touching the woman's breasts buttocks through her clothing while thrusting his penis against her.

Mr Bevan said he saw the woman and Morse kissing but did not recall hearing the accused ask her to go to the bathroom with him to wash her hands.

He said he was not surprised when Morse appeared with the gun, which belonged to him, because he liked to show it off.

"Nick kept clicking it, saying it wasn't loaded. He pointed it at me. I knew it wasn't loaded," Mr Bevan said.

Crown prosecutor Gary Hevey asked Mr Bevan if he saw the gun pointed at the complainant, to which he said, "No. The only person it was pointed at was me".

Mr Bevan said after Morse appeared with the gun, he went outside for about five minutes to have a cigarette and urinate, leaving Morse and the woman inside alone.

He said when he went outside, he did not see the gun in Morse's hand but he did not see him put it away.

While being questioned by defence barrister Shane Kennedy, Mr Bevan said Morse often used colourful vocabulary, he did not pressure or threaten the complainant and their kiss was mutual.

Morse has pleaded not guilty to five charges including two counts of sexual assault and one count of rape.

He has admitted four weapons charges including being a non-prohibited person possessing a handgun, dealing with a sawn-off shot gun suspected to be the proceeds of crime, and possessing knuckle dusters and cartridge ammunition.

The trial will continue at the County Court in Ballarat on Monday before Judge Howard Mason.

Two prosecution witnesses, including the police informant, are expected to give their evidence.

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