Suicide Blonde by Darcey Steinke

Jesse is a 29-year-old adrift in San Francisco's demi-monde of sexually ambiguous, drug-taking outsiders, desperately trying to sustain a connection with her bisexual boyfriend. She becomes caretaker and confidante to Madame Pig, a grotesque, besotted recluse. Jesse also meets Madison - Pig's daughter or lover or both - who uses others' desires for her own purposes, and who leads Jesse into a world beyond all boundaries.