I know that its a STD and that both men and women can have it, my question is, if for example you have sex with only one man forever (being a man yourself) and he´s not infected, in theory you would never be infected even if you dont use protection?
Yes.. but the catch here is that 1. you don't know if the man is lying 2. you don't know if the HIV test could be a false negative (meaning that he has HIV, it just didn't show up.) 3. He could just not know his status. There are other ways of getting HIV. He could've been exposed to blood at work and became infected without even knowing. (It's rare, but it can happen.) So, until you FOR SURE know somebody's status, it best to use protection.
If, in theory, humans were always 100% faithful -- and for argument's sake we'll assume the only way you can contract HIV is through sex --, then yes.. if you're in a monogamous relationship you will not be infected even if you don't use protection. However, humans make mistakes, humans are not always faithful, and humans lie. That's what makes your theory different from reality. I get you, I've been thinking about the same thing, and personally I doubt that if I trust someone and I'm in a relationship with him, I will always use protection, but to say you can never get infected just because you're in a monogamous relationship, that is simply not true and I think everyone should realize that.
This. ALWAYS be careful with sex, that guy that you think you know everything about may have a secret you don't want to have. Heh... Heh, unless genetic mutation occurs and the OP and his BF are the new start of HIV. Well I guess you did say "in theory" though. All the best.
The only person whose monogamy you can be sure of is your own. The question is- are you so sure of your partner's faithfulness to you that you're willing to put your life on the line for it? We see people who cheat all the time, yet we always believe that it won't happen to us. And of course, HIV isn't the only thing to worry about these days.
You'd be safe only if he really isn't infected (you'd need him to consent to periodic testing, I'd say at least once a year, to be completely sure of that) and if he never has sex with anyone else (which you honestly can't know). And we haven't gotten into the subject of the many other diseases that can be transmitted via sex. The list is boring and scary. So, in brief: no matter how much you trust him and love him, you should love yourself first. If you guys are in a committed relationship, he should be able to understand and respect that you are serious about caring for your health.
How does a needle become contaminated? Must it be a hollow needle so that the blood isn't exposed to the air?
A needle must be sterilized after it is used for safety, the contaminants will just simply stay on the needle. Sterilization can occur from things like rubbing alcohol and holding a lighter under the needle, burning it. Never share needles. All the best.
