Ernesto

Ernesto is part of Michele's group of friends. He has full blown AIDS and is very sick when we're introduced to him. In telling Antonia how he got sick he tells her the exact date it happened, and she's surprised he remembers so well. He explains to her that he did it on purpose. That he wanted everything of the guy, even his illness. He basically was in love with someone who treated him like sh*t, leaving him often, but every time he tried to leave the other guy would come crawling back. He says that when the other guy heard he got sick, he disappeared. He tells Antonia something like "I don't know where he is. But he knows exactly where I am". She then points out that a lot of people who are on his meds are living very good relatively healthy lives, and he says that it's the ones who are careful about taking their meds, and Antonia tells him that maybe he should be careful too.
It later transpires, when he is rushed to hospital and is very sick, that this lover has died from his illness, but none of the others ever had the courage to tell him, fearing that he would let himself die. Michele explains that everyone has always abandoned Ernesto, even his parents.
Antonia goes off to tell him the truth at once. SHe explains that the reason his lover never came to see him was not abandonment, but simply that he had died. This restores Ernesto's will to live. By the end of the movie he is taking care of himself and looking much better. Before leaving Antonia tells him that in a month he'll be well enough to be up and about and chopping the onions.