constantly exposing oneself to such damage will increase the risk of AIDS
people who get such body decor are different from "regular" population in various ways
if you are gay and you like to get tattoo and body piercing, you'd better watch for yourselves
you never know who come across what and what you will get
in a way, your friend belongs to a population with higher risk of development AIDS
but he may not have AIDS after all
So, it takes time to find out