Do I need to disclose personal information about my life to parents I will be babysitting for?

I’m looking for a few babysitting jobs since I am a stay at home mom. However, I do live with my domestic partner. Am I obligated to tell the parents I will be babysitting for that I am a lesbian and that my partner lives with me, even if she will not be around the majority of the time that their kids will be there?

BTW: I do tell them I have a roommate, I just don’t disclose that she is my partner.