Welcome to the forum!
I want to open up to my husband about agreeing to a poly relationship, but I don't know how to ease him into it without freaking him out and thinking I want to end things.
When my wife first raised the possibility of polyamory, I already knew she had been learning about it, through online friends of hers who - aside from other interests my wife shares with them - have been practicing polyamory.
She brought it up as a question for consideration: "I've been learning about polyamory. Here's how I understand it. Is this something we might consider?"
I was freaked out, at first, but mainly because the idea was unfamiliar. Since she raised it as a possibility that
we could consider
for our relationship, it did not otherwise seem a threat to our relationship. If anything, I was worried that I could not be open to relationships with others without threatening
my ability to maintain my relationship with my wife and with our children.
I started reading about polyamory, learning all I could . . . and a week later, I raised the possibility of actually making the change.
It was kind of a soft sell, on her part. I wonder if that kind of approach could work, in your case?
I just want to expand our relationship to include what I think we both want/need, which is another relationship that fulfills us in other, but needed, ways. Any advice would be very welcome.
It might be helpful, at this point, to expand your understanding of what your options are. You say "another relationship", but does that mean you and your husband would both have a relationship with the same person?
That's a common approach, as you'll discover by reading the forum, but can be very difficult. (See all the various threads about triads and "unicorn hunting".)
Another possibility is for each of you to develop other relationship
s, independently. That's the model my wife and I have followed, and it has worked well . . . for us . . . so far.
All the best to you as you figure all this out.