In Portugal, public and political discussions about same-sex marriage have been going on since the 1990s. In 2010, same-sex marriage was legalized under intense dispute since it excludes same-sex couples from adoption and reproductive rights. During parliamentary debates, political parties and civil organizations linked to the Catholic Church resorted to conflicting ideas of ‘equality’ and ‘difference’ to advance their claims. In this article, we analyse the contents of petitions, bills and parliamentary proceedings concerning the legal recognition of same-sex unions, highlighting the presence of conflicting notions of equality linked to pervasive beliefs about the inadequacy of homo-erotic desire and practices