Cynthia Nixon and her fiancée Christine Marinoni welcome a son Max Ellington Nixon Marinoni on Monday. Marinoni is the birth mom and according to Nixon's rep, "Christine and the baby are doing great."

The two women have been together since 2004 and they announced their engagement during a rally for same-sex equality in New York in May 2009.

"We could go to Canada, and we could go to Connecticut, and we could even go to Iowa, but we don't want to," the actress said at the rally. "We want to get married right here in New York City, where we live, where our kids live."

The Sex and the City star is already the mother of two children, Samantha, 16, and Charles, 9. She gave birth to them when she was in a relationship with photographer Danny Mozes. They split in 2003.

Congratulations to the new moms!