Awesome! It was a bit tense there for a bit but in the end you guys made it through this patch pretty ok then and arrived at a new understanding of each other and with the knowledge that this relationship CAN handle rough conversation and not have partners wig and bail.
That will help you both in confidence for the next time, whenever that one hits. You can both go "Remember the time... THAT hooha? I think this could be like that. Rough convo but we can make it through if we stay calm and preservere."
It sounds like he's coming to terms that he's more polysexual than polyamorous and you both better for having shared vulnerable. Emotional intimacy had, new understanding reached. New plan of action made -- now off to execute and see how the plan serves you both.
Still check out those communication/conflict tools -- but I am so glad you sorted this one out and could move it forward.
Good on both of you!