I'm going to look inside my anus and pull out some free advice, complete with conclusions about information I do not have, assumptions about people I do not know, and judgements about people who are not here to tell their side of the story.
Oh my darling - it's really clean up in there. It must be because of all the psyllium fiber capsules I ate.
Alright, fuck all that, I'll just tell you what I think.
You: maybe hierarchy, maybe not. if hierarchy = yes, primary preferred
D: evasive. tells people what they want to hear. if questioned with specifics, gives as little information as possible
R: you don't know they're in love, she doesn't know you and D are in love. I guess that makes you both even (but not the kind of "even" that it means to be in a "non-hierarchical" relationship)
I read your story twice just to make sure I wasn't imagining any of this. To answer your title question/s, is it dishonest and wrong? I suppose that's one way of putting it. If I were sugar-coating it I mean being "open-minded" about it, i would definitely say that there is more to this than D is sharing with you and R. Is it "standard practices"? I don't think I can answer that seriously with a straight face, so I'll use a rhetorical question: What do YOU think? Do you think it's "standard practice" for mature adults (cue lectures about ageism from the peanut gallery) to conduct their close personal relationships this way? Has it been your personal and anecdotal experience that this is a "standard practice" when it comes to fostering a healthy environment for oneself?
Anyway, it sucks that you're going through this and I hope you make choices that put your own needs before the needs of a person you've only been with for a year or so, whom you don't even seem to have very good communication with.
On the other hand, you could just accept him for what he is, not what you wish he were, and just have fun and share his company and sex. But don't merge your lives (especially finances) together and don't have any expectations that he'll "be there" for you through thick and thin. Find someone else to create a home with, who will pick you up when you miss the last train home or go to the store and buy the juice you like when you're sick.
You can't "make this work" the way you want all by yourself. Even if you do all the "right" things, the other people will still do what THEY want.