t understand your comments about his oxygen mask. HIV
is not caught by providing that sort of care to AIDS
patients. If your hand are going to come into contact with body fluids, standard precautions are to wear protective gloves -- but for the mask, it would be sufficient to just wash your hands or use an alcohol gel (like Purel). Anyway, your own urethra of course would not be at risk from this sort of contact.
Finally, knowing your partner has HIV, perhaps you know more about hs infection.