Greg, you are not understanding what I am saying. Either that, or you are deliberately missing the point.

If you are going to have multiple partners, you should always use a condom.

If you are in a long term committed relationship, and if you have had any sexual partners prior to the one with whom you are sexually involved currently, you (and your partner, if he or she has also been sexually involved with anyone prior to you) should be immediately tested for HIV/AIDS, and again in about six to nine months (incubation time). You should use a condom until both tests come back negative for both of you. Then, as long as both you and your partner remain only sexually active with each other, and no one else, you can safely have unprotected sex (assuming neither of you uses injectible drugs or has received any tainted blood through a blood transfusion, or has been accidently pricked with a contaminated needle, or has engaged in any other kinds of non-sexual high risk (for HIV/AIDS) behavior.

Aside from complete abstinance, this is the ONLY way to prevent the transmission of HIV/AIDS through sexual contact. Everything else is just a stupid game of Russian roulette.