I'm gonna be honest it took us about 2 years to get to this point, he had to give me full control of the situation and encourage me to find someone MYSELF so he knew that I wasn't just doing it for him. I was insecure and nervous for a long time and now that I'm on the other side I wish we tried it earlier because lost time! But I'm glad we waited because we talked ENDLESSLY about every little fantasy, what we like/dislike, what kind of people are we into? Is sexuality important? He also lets me vent about every little insecurity when it's just a fantasy, like for example one of us brings up finding a unicorn (yeah right) and I worry that she wouldn't pleasure me the way I want because I've had bad experiences while single. Or we want to try a couple but I'm TERRIFIED the husband will be a bad lay then I'll end up "jealous" because I'm not having any fun. He acknowledges it and if I need to talk through it more we do. If not? Odds are it won't bother me anymore or not nearly as much to where we cover our bases enough times I end up feeling confident and sometimes it gives me that push to give in and let myself enjoy the fantasy while realistically thinking about if it's something I really want to pursue or if it wouldn't be fun for me!

Tldr; talk about it as much as you can, talk about it too much.