The bf however flipped out. He went into what I've seen people here discuss about "why am I not enough?" and then proceeded to say I won't be happy until I catch some disease.
Haha....
Oh dear... Charming!
I'm sorry (for you) that it went down that way with your bf. One thing I could say is that, from personal experience of being the 'new person' coming into a long-term marriage, your proposition may be more difficult for your boyfriend to cope with than it is for your wife.
For instance, your wife has already gone through the process of watching you get involved with someone else now. Granted, she's also involved with him... But your boyfriend hasn't yet seen you involved with anyone
new, right? The fears of replacement may be stronger for him because he's used to being the one you are directing your NRE towards, and now his time 'in the sun' may be over. He becomes old news. It's just something to think about.
It's also worth considering how you treated your wife when you were first falling for your boyfriend. Did everything go smoothly? I know that in my case, my GF (who had been married for 13 years) really became wrapped up in me and revealed many of her marital problems to me. Whilst I felt extremely special and adored at the time, when it came time for GF to introduce someone new to our mix, I instantly recalled those times and suddenly feared that she would be telling her new lover how bored she was of *me*. Another thing to think about!
Of course, it could also be that your boyfriend stands firm in his wish to be a polyfidelitous triad... or to have what he considers an 'equal' triad, where he has someone else just like you and your wife have each other. It's not difficult to empathise with that position - it surely is less emotionally taxing for him to consider finding someone else than consider you with someone new.
If his harsh comment was relatively out of character, try to think about why he was so scathing. He's threatened. He's lashing out. Perhaps he felt betrayed and shocked that you do not share his core values about poly. Perhaps he has made a judgement - why might he think you are an unstoppable greedy fiend? What has led him to this opinion?
My advice is to talk to him again, with compassion, and try to find out exactly what it is that is scaring him. I hope it goes better the second time around.
Finally, as for whether or not you are being greedy - well, yes and no!
In either case, it doesn't matter. What I would say is that it's never a good idea, and rarely ethical, to add additional people when existing relationships have cracks. By this, I don't mean jealousy or insecurity, but the workings of a relationship - sex, intimacy, dates, fun, friendship, commitment, etc. If all of that is going well, it's a better time to explore others than if something is missing. Adding someone else almost always highlights the cracks.
EDIT -
I just read your other thread and now understand that you had an affair with your boyfriend for a few years before telling your wife and becoming poly. I'd hazard a guess that this has something to do with your boyfriend's reaction. Could it be that he thought he was something special to you - so special that you would cheat - and now feels used, less special or tossed aside? Could it also be that your boyfriend, deep down, judges your decision to cheat and feels that you have no self-control? These are things to find out!
