The former `Sex and the City` star is engaged to her long-term partner Christine Marinoni - with who she has an 11-month-old son Max - and despite angering many people, she insists it was decision to become a lesbian.
Cynthia - who was with former partner Danny Mozes for 15 years and had two children, Samantha, 15, and nine-year-old Charlie, with him - said: "I gave a speech recently, an empowerment speech to a gay audience, and it included the line `I`ve been straight and I`ve been gay, and gay is better.`
"And they tried to get me to change it, because they said it implies that homosexuality can be a choice. And for me, it is a choice. I understand that for many people it`s not, but for me it`s a choice, and you don`t get to define my gayness for me. A certain section of our community is very concerned that it not be seen as a choice, because if it`s a choice, then we could opt out.
"I say it doesn`t matter if we flew here or we swam here, it matters that we are here and we are one group and let us stop trying to make a litmus test for who is considered gay and who is not."
Cynthia, 45, insists she hasn`t always been gay and finds it "offensive" that people say she has.
She told The New York Times: "Why can`t it be a choice? Why is that any less legitimate? It seems we`re just ceding this point to bigots who are demanding it, and I don`t think that they should define the terms of the debate.
"I also feel like people think I was walking around in a cloud and didn`t realise I was gay, which I find really offensive. I find it offensive to me, but I also find it offensive to all the men I`ve been out with."