More often then not young people will just ask and trust. Unprotected sex is more common than people think since msot girls are on birth control and the guys take the girls word and vice versa.
This article is totally out of touch with reality. You can't view this stuff in a vacuum. There is a dating/mating ritual. It involves, usually, going out, drinking, music, mood, excitement, adventure. Or else maybe it was just me. Anyway, you don't wait two weeks for blood tests. You throw caution to the wind and live life. I'm not saying it's safe, or moral, or the way to meet a wife or husband. But that's how it takes place. And even if it's a little slower, I still seriously doubt ppl are gonna get blood tests. It just doesn't happen. And not only do they not ask others to test, they don't test themselves either. And most heteros are not dying of AIDS, so they see no reason to change. The real high risk behaviors are drugs with needles, prostitution, and gay sex.