Scarlett has two HIV tests a year
Scarlett Johansson says she is "open-minded" about sex - but not promiscuous.
The starlet also revealed that she has an HIV test twice a year, and urged others to get checked regularly for sexually transmitted diseases.
In an interview with Allure magazine she opened up about her relationship with Black Dahlia co-star Josh Hartnett.
"Josh is very sweet," the 21-year-old said.
"He's a good boy. A great person. I'm very lucky and I'm very happy. "Contrary to popular belief, I'm not promiscuous.
"There does seem to be a mistaken belief out there that I am sexually available somehow - which is not to say that I'm not open-minded about sex.
"Yet I wouldn't say I'm a serial monogamist, either. I mean, I went through periods of time when I was, ah, single.
"But when I'm in a relationship, I'm in a relationship."
The Lost in Translation star said monogamy might not be natural, but that she believed it was worth striving for in a relationship.
"I do think on some basic level we are animals, and by instinct we kind of breed accordingly," she told the magazine.
"But as much as I believe that, I work really hard when I'm in a relationship to make it work in a monogamous way."
She also said: "I get tested for HIV twice a year... One has to be socially aware.
"It's part of being a decent human, to be tested for STDs.
"It's just disgusting behaviour when people don't. It's so irresponsible."
