"There are people who will try anything to create news," said Zan, who belongs to a small left-wing party.
He is hoping to introduce a proposal for same-sex marriage in Parliament; its prospects are vanishingly small.
Zan and others attribute the official indifference or contempt for gay rights partly to the influence of former Prime Minister Silvio Berlusconi, 77, who tried to make a political virtue of hosting "bunga bunga" parties and sleeping with women a third his age (or younger — he has been convicted of paying for sex with a 17-year-old girl).
Berlusconi once proclaimed that it was "better to like beautiful girls than to be gay." Many of his supporters are men who admire his wealth and the bevy of young beauties on whom he has lavished gifts and political appointments.
Critics say Berlusconi has coarsened civic life and fueled a widespread culture of reflexive machismo.
"Here in Italy we've had 40 years of [conservative] Christian Democrat governments and 20 of Berlusconi," said Zan. "It's time to change."
But building a grass-roots movement and enlisting high-profile supporters has been difficult. A few well-known figures in Italian society have come out of the closet, including singer Tiziano Ferro and fashion designers Domenico Dolce and Stefano Gabbana, but few lend their names to the cause.
Gay role models are difficult to identify, though sympathetic gay characters, not just stereotypical ones, have gradually begun appearing in films and on television. There are now two openly gay regional governors, both elected, surprisingly, in the supposedly more traditional south.
One of them, Nichi Vendola of Apulia, told an Italian newspaper last year that he was afraid to go out alone for a walk at night in Rome because of potential gay-bashing.
A nationwide survey of 4,000 high school students by Rome's Gay Center found that 5% identified themselves as lesbian, gay, bisexual or transgender; of these, nearly three-quarters said their families and schools would not accept their orientation, and one-third said they had contemplated suicide.
The death of Simone D., who was believed to have suffered harassment at the hospital where he worked as an intern, drew hundreds of activists and allies onto the streets of Rome demanding legal rights and protections for gays and lesbians.
But the government did not respond with any new promises. The power-sharing coalition is hanging on by a thread, making it unlikely that lawmakers will go any further than the hate-crimes legislation under consideration.
Signore, the Milan writer, said the political situation was complicated, but that "is not an alibi for not doing anything." He credits much of his political awakening to the year he spent living in Los Angeles, in 2009, when he was 20.
"I knew that it was far, far away, but I would never imagine that it was so different from the world I was used to. I saw gay people having babies. I saw families," he said.
"Everything seemed so natural," said Signore, who discovered the world of dating, relationships and happy everyday existence. "And I think I brought that back with me. If that is really possible … I want to have it in my country too. I said to myself, 'I can have that.'"