My daughter too is a single mom, and because she is a single mom, I have spent as many hours with my granddaughter as my daughter has. I am my daughter's partner.
I have never been able to lie successfully. Until it came to the welfare of my daughter and granddaughter. I lie by omission. When my granddaughter's father or her grandparents have come to visit with her, I pretend to be single. They know my partners are my best friends, they don't even suspect there is anything more going on. I would never allow even a hint of what our relationship is to be whispered about. If I thought my daughter could lose her daughter because of my behaviour or living arrangements, I would lie to God himself, and be convincing.
My daughter knows what our relationship is, and has never asked us to behave any differently around our granddaughters father or parents, but having a little more wisdom and seeing how the world really works, we know that our relationship could have a bearing on whether she goes to court or not.
She has recently began dating a man that is closer to my age then hers. He has two teenage sons. On their first date, very hesitantly she told him of her "parents" relationship. I met him for the first time this weekend, and being a single mom, of a single mom, I did what had to be done. I had the "talk". My daughter had told me a little about his legal affairs with his soon to be ex-wife. From what I've heard, if this woman even had a hint of what he was bringing his children into, he too would end up in court. It doesn't matter that we are good and loving people, that we would treat his children as our grandchildren. It only matters that our relationship could be used against him. I felt that I owed it to him to tell him that my partners and I would never allow our behaviour to be an issue. The gratitude on his face was beyond words. He assured me that he has no problems with our choices. He sees the love we have for each other and "our" daughter, but he had to admit, being a parent, he was also looking ahead to what he could be facing. I don't blame him. I think about it everyday when it comes to my daughter and granddaughter.
Pretending to be single doesn't take away from my partners or myself. If it means that "our" daughter doesn't have to defend herself or parents in a court of law then we are willing to do what has to be done. None of us could live with losing our grandbaby because we couldn't pretend to be just friends.
I know lying is hard, and as a general rule I would be the first to call anyone on it. I do know that when it comes to our children, or in my case grandchild, I'm with Redpepper when she says," What they don't know won't hurt us."