Hi broncofan, and welcome to the forum.
I agree with the other respondents: kudos on your approach thus far.
It may feel like you're on shaky ground, but you're coming from a place of honesty and integrity. Way to go. At this point no one can predict the outcome, but you're moving in the right direction. Open, honest, loving and considerate of each person's needs. Seriously, way to go.
There's one thing you wrote that concerns me.
Originally Posted by broncofan
. . . He flipped out that I had told my husband . . .
This is a huge red flag. How did he think the three of you were going to form polyamorous relationships without your husband being in the loop? Are you sure your #2 isn't just looking for a clandestine affair?
Again, welcome to the forum, and best of luck to each of you. I hope you find what you seek.