"He (Bieber) rang me and invited me, asked if I wanted to go to his house for a party."
Asked if she and Bieber had kissed, Barbosa responded, "What do you think, if I was sleeping in the bedroom, just me and him?"
She said they had slept in the same bed, but refused to comment on whether they had had sex.
Barbosa, 26, said she filmed the video of a sleeping Bieber on the morning after.
The now-famous clip was not the only drama the singer has experienced on the South American leg of his Believe world tour.
Bieber stormed off stage in Sao Paulo, Brazil after being hit in the head with a bottle, and was ambushed by a topless male fan at a show in Rio de Janeiro.
Bieber was charged with vandalism for spraying graffiti on the outside of an abandoned Rio hotel.
On Saturday he was asked to leave his Buenos Aires hotel because of the number of fans who were camping outside on the street, and on Sunday he had to cut short his show in the city. Bieber said he had been suffering from food poisoning.
- WENN