hiv transmission

hi folks,am just curious about how easy or how difficult is it to get hiv in case of partial exposure to hiv infected body fluid in ur genitals.For instance,see u had protected sex with an hiv positive female and by chance her vaginal fluid comes in contact with your penis which does'nt have a sore or cut.what are the chances in this case?are there any specific amount of body fluid required for an infection to occur?

[Teak]

You don't contract HIV having protected sex.

[shane_o2o]

but for instance,if u rub her vagina and if the same finger touches ur penis after taking the condom off,what are the risks invloved?