I really encourage you read some threads on this. We have talked about names, secrecy, all of it.
My boy is seven and he came into his own name for Mono. I told him after about a year that I love Mono and that he is family to us. I told him that people come and go. My ex wife had a girlfriend that cheated on her and left her high and dry. She came to stay with us for awhile and I went and stayed with her so that she could grieve and be supported. We told our boy that his auntie Wendy was not going to be around any more and that some people come and go. It doesn't mean we don't love them after they are gone, but they need to move on. Sometimes we do to.
Its not really that different than any other relationship dynamic. Its a matter of confidence in what you are creating. You know what that's like if you are lesbians. Kids get that and also feel confident. There is also no rush to *make* it work. Being a good host to others is all it takes; welcoming, respectful, considerate... the rest manifests. If others don't give that back then its time to move on and not involve them in your life I think.
I have written a bit on this in my blog and in a thread about being a good host. I can find it if you want. I wouldn't mind reading it again actually. But I can't right now. I'm on my phone. Again, I would highly suggest doing some reading here. Lots of really good input.