I am now the same as you, enjoying my husband with another woman. The first time was difficult for me, even though I had a boyfriend for two years at that point. And the first several wouldn't let me participate or even watch.
Copying from a previous post of mine:
Unicorns are out there you just need charm, luck and patience. I snapped when a girlfriend of mine said she thought my husband must be fun in bed and I said "That could be arranged." She took me up on it and I learned to love the jealousy. This first friend didn't let me watch, but we all enjoyed the experiences in our own ways. It ended when she got serious with her boyfriend and couldn't see screwing my husband any longer. But we went out with them as a couple (I don't know if she ever told him) and we remain friends with her and her husband, a different guy (who does know).
Both hubby and I enjoyed the way things had gone (and at this point I wanted another "jealousy" fix), so I brought another woman, an acquaintance, more closely into our life. I went to lunch and shopping with her, then introduced her to my husband. We "dated" her together, we took her to dinner, the theater, and on vacations, which we paid for. I left her alone with hubby from time to time to show that I had no problem with them being together. It went nowhere sexually, but the fantasies between hubby and I were breathtaking - for him, me describing her body from the few times that I saw her undressed; for me, the fantasy images of them screwing. We still got together from time-to-time for a few years afterwards with no expectations of sex until she moved away.
We repeated the dating pattern with fifteen or so more women, and four took us up on the invitation to have sex with hubby. One other didn't want me present, and I respected that; the other three not only let me watch but either immediately or eventually had a Lesbian relationship with me as well. (My second great sexual awaking). One of the women was Clair, with whom both hubby and I became sexually and romantically involved. Clair joined us along with my boyfriend Red to turn our strange ménage à trois into a poly family (especially when Clair became pregnant and had our first child, with me closely behind).
Of all the women that we "dated," none have expressed any regrets or animosity towards us. We were looking for relationships, and found them whether it led to sex or not. We are on good terms with all of the women who we are still in contact with.
You have to be generous, kind and enjoy wherever it goes. We spent time and money on women who I befriended, but ultimatley had no interest in having sex with either of us. We created opportunites for her but never, ever pushed or made her feel that she owed us. It was all fun; even the ones who had no sexual interest in us fueled some fantastic fantasies. The woman who you are looking for is out there; be nice and generous. And enjoy interacting with people whether it leads to sex or not.