Welcome to our forum.
I suggest you keep those communication channels flowing, as communication is highly important to any kind of poly relationship. As for "coming out," that's completely up to you; you don't have to tell people if you're not comfortable doing so.
I would spend some time reading various threads on this site (perhaps using search and tag search sometimes), and just post if you have a specific thought, question, or concern somewhere. Right now, it sounds like the three of you have a promising relationship.
Glad to have you onboard,
Love means never having to say, "Put down that meat cleaver!"