If the lady dries up while you are in her, then her arousal is going down, but it makes sense to put a dab of lube inside the condom (assuming you have some on you - usually this isn't the case in a car, dept. store, etc.), just be careful not too much as the condom will fall off.
As for the HIV being curable, we'll not 100%. Undetectable, yes, not 100% curable. It's preventable now as well; to some degree. However, I would not say contracting HIV and living with it is not going to have a negative effect on your life; it will. Herpes, people can live a normalish life, HIV/AIDS, nope. HIV/AIDS is still a death sentence the virus is mutating. There are actually three strains of HIV, HIV I, HIV II and HIV III.