J may need his own primary.If he is involved with you and wants the "real" gf, he may be barking up the wrong tree. He has to realize he will be and is a secondary for a while at least.
I think some questions need to be asked
1 - Is J really non-monogamous
2 - if so, does he feel the need for a primary or understand what it means to be a secondary to someone.
3 - if not, then is he expecting you to be two peoples primaries. Thats where we get into murky waters. We do see people who can navigate the multiple primary scenario, but most run into plain old timing issues. If J wants a real, true to life primary, and you are busy with husband and kids, and family. As mono on this site has said, he finds it more reasonable to be someones secondary, as a monogamous person, because he has had all the marriage fixings before (please mono feel free to correct me)
I know that it all seems like so much work right now and reading all this must make some of you think "why is she bothering".... and "oh what a hot mess" and "she doesn't get it"... and maybe I don't... and maybe it is..
I am not
. Honestly we have seen bigger messes and lesser messes. Relationships by their very nature are hard. Bringing in more people extends that complication further. Non-monogamy is not the easiest relationship structure to be in. Its one you really have to believe in for yourself.
Honestly, this has been what, a few weeks right? I think there is a dose of patience required on everyones behalf. You are far from a critical breaking point. Maybe scale back the pace at which you guys are moving. I think B just needs to catchup. For the record, a good rule of thumb, if you see him catching up, don't make another leap, just stand there for a bit with him, enjoy the settling a bit, and then move forward. If he feels like you are doing this together he might make a lot more progress.