Its good that you and your husband are open to the conversation bc thats really the biggest hurdle that most people come up against.
I would suggest you ask your husband why he’d be ok with another woman but not a man in a 3 some. Is it a confidence thing where he doesn’t want to be in the vicinity of a naked penis or does he want all the attention of 2 women?
I think men think 2 women are automatically going to have sex, but not every woman wants to do all things with other women. So you really need to discuss what you both want to get from it. And be honest about it, bc theres no point in not being honest.
I appreciate you’re maybe just thinking out loud at the moment and not at a stage where you want to jump in.
I would suggest joining fabswingers .com, its a swinging site that has forums to chat, you can chat 1 on 1 with other people and arrange to meet if you like them. Think of it as tinder for sex. Some people and clubs hold events, clubs are probably the safer option until you get a bit savvy with it, bc not every person you talk to will be genuine and a lot of people just like the fantasy but I’ve met a lot of good people from it. I suggest you look for swingers clubs, possibly in your area, there are also reviews of the clubs on Fab.
Have a read of Richys experience with fab and swingers clubs, the Richys were a few more steps ahead of you, but its a good read and a good first hand experience that you may get something from.