Well, me and my girlfriend personaly dont use condoms. but since its a 3some we figured we would. but now to the question. we plan on having a 3some in a few days with a female friend of ours. if im using a condom and im having intercourse with one girl then i dont change a condom or anything and put it into another female would they get an STD if the first person had it or how would that work? does the std die on oxygen?