During a rally for gay rights in New York City over the weekend, Sex and the City star Cynthia Nixon announced she is engaged to girlfriend Christine Marinoni, according to a report by E! News. At the rally, which was held to draw support for same-sex unions in New York state, Nixon revealed she became engaged last month. The couple has been together since late 2003. Nixon and her Sex and the City compatriots — Sarah Jessica Parker, Kim Cattrall, and Kristin Davis — are set to begin filming the sequel to the big-screen smash later this summer.