Scarlett Johansson

Scarlett Johansson gets tested for HIV twice a year.The 'Black Dahlia' actress insists she is not promiscuous but has the test because she is a responsible human being.Scarlett, 25, revealed to Allure magazine: "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 disgusting when people don't. It's so irresponsible.But contrary to popular belief, I'm not promiscuous.The 'Scoop' actress - who is dating her 'The Black Dahlia' co-star Josh Hartnett - also claims that monogamy goes against nature because people "are like animals." But despite her liberal views on sex, Scarlett insists she is happy being with just one man. She added: "I do think on some basic level we are animals, and by instinct we kind of breed accordingly."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."Scarlett insists she is very happy with Josh and has no plans to be single again anytime soon. She gushed: "Josh is very sweet. He's a good boy. A great person. I'm very lucky and I'm very happy."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." She added: "I mean, I went through periods of time when I was single. But when I'm in a relationship, I'm in a relationship."