I would note a couple of things.
1 - not everyone is cut out for group stuff. Its not natural for everyone, with everyone. In some cases the person with the supposed reigns needs to give up the control. His.. attempt at scheduling a threesome would be annoying at best. Especially sinces its all so new. How many people planning and itemized the losing of their virginity. Not too many. There has to be a natural flow and connection. .. FOR EVERYONE...
2 - poly isn't about threesomes. It could be.. it can be.. and it is fun.. but you don't have to do threesomes to be poly.
Your meltdown, the way you describe it, seems warranted. His itinerary is a very naive view on sex. Shockingly immature.
I have to admit I am kind of chuckling. If I had ever tried that, in any of the situations I have been in, they never would have happened... AND.. I likely would have ended up slapped.