Hi Sani and welcome !
Don't think you'll have to worry a lot about folk here being "kind". Pretty darn respectful and kind bunch here from all walks of life.
So yea - you have a dream and your name isn't Martin !
But it's a long way to poly yet.
The fact that your hubby seems as encouraging as he is - well c'mon.......think about it ? One man - two women ? Imagine that.
Now there's nothing inherently wrong with that - far from it. But in starting down this path I'm thinking this might be a good point to get involved in Honesty 101. Call a spade a spade - and start getting used to doing so.
And while you're at it, it might be fun to just bring up the possibility of you discovering another male lover ! Good check for the reaction and a lead-in to some great discussion. Good chance to see how serious hubby is about you having "someone" in case something happened to him.
Last I knew, "someone" was a gender neutral term ?
But happy you guys are starting this discussion, because it can in many cases take your own relationship to another level. Even if no 3rd, 4th etc party ever actually enters the picture, the discussions you have and insights you gain will be priceless.
Keep studying, keep talking and feel free to ask/contribute here anytime !