You say it is not quite common. I actually thought I was completely alone in this situation!
I have yet to hear of anything like it, ever, in my life. It was new to me. I just sorta fell into it without any prior thought. It just seemed right at the time. Natural and pure, no agendas, just everyone looking out for the others, with a bond that I can't even explain.
Since I have kids of school age, I do get questions like, "Who is that?" My kids always tell people their uncle lives with them, and at times some bold people will say, "He is not your real uncle, because he is not your mom or dad's sibling." I can't even imagine saying that to anyone ever. The nerve of some people!
I guess, for a long time now, I've felt like I've had this burden of a secret on my shoulders. It is probably a weight I put on myself. I sometimes have a hard time with the fact that the mono won't ever be "more," in other people's eyes. I am not sure why that matters to me, because his concern is what we have together and he needs no other approval or recognition. Knowing I am with him is all he needs. I wish I could be more like that, too.
My husband is a pure saint and tells me we all know what we have, share, etc., and why is more love bad? If other people surmise, question, etc., he doesn't really care.
Another issue for me is my kids, who are my driving force in life. I would never want this to effect them negatively in the future. Mono and my husband think the more people they have to truly love and support them is only a benefit.
As for the ex, well, she is a certified crazy to begin with, but she tries to brainwash her and mono's kids into believing we are all whackos! She also tries to make them and everyone believe we are possibly mooching, to take from what they would have had, and that my family is more important than them, and on and on. They are getting older, and we just try and stay consistent, and two have seen the light. But it has been a journey and magnified because of her, to say the least.
So... you're right. I am struggling. I am usually a pretty independent, confident person, but I sometimes have a hard time working through and processing this situation.
As for my family and neighbors, I think I was more friendly and close in the past, but as our triad gets closer, I get more paranoid of questions and have somewhat retreated and am more secretive about what we do. My family also gets super jealous and questioning about why I spend so much time with him and not more time with them. Usually, it is because, as I get older, and we have super busy lives, when I have free time, I want to be with them and my children, because they lift me up and make me a better person. If I go with my neighbors and other family, I am filled with anxiety and worry about the questions to come.
I look forward to your insights on my situation!