You said the two of you have had some naughty sex talk now and again, what did the talk include?
Specificaly, did it include you taking it from another man or anything along those lines?
If so, I think he may be open to the idea in fantasy. That is where the idea has to start IMO. The crossover can be long, if not impossible, between fantasy and reality because of all the social conditioning we get telling us how wrong it is. Also jealousy is another big one for a lot of couples.
For me, jealousy went away when I became not only secure with who I am but also totaly secure in our relationship.
When I see mrs naughty rocking a guys world as well as getting hers rocked back I am turned on by seeing her give/recieve such pleasure. It's simply amazing! facelick
You know your husband better than us. If you haven't brought the idea up in sex talk, then try it, but only if you think he won't blow with anger just by the mention of it. Not by telling him YOU want to try it but if HE would like to see it. And not only see it but help in every way possible.
Plant the seed, but plant it carefully.
If you two already have had naughty talk about it during sex and it really turned you both on, try asking him during your naughty talk if it is something he really wants to try?
If he asks if you do, tell him only if he does and you want him there and helping.
I will never forget the day mrs naughty told me she was "Game" for an MFM.
We were having our naughty sex talk and she said "Do you really want to see me take another guys cock?" I said Absolutely!
The next words out of her mouth was "We can make that happen".
I think I came immeditately

.
Anyway,
The next day I started to think about it and got scared. I told Mrs naughty that the talk we had the night before was just fantasy and I didn't want it to happen, even though I did.
She was fine with that but now I knew she was game and she put the ball in my court.
After several internal arguments for and against giving this a shot I decided to go for it and told Mrs naughty she could find some one she was interested in and set something up.
She did, and we did. And it was more amazing than what I fantasized about. We both had a wonderful time and continue to get great joy living out our fatasies together.
These are just my thoughts. Every realtionship has its own dynamics. Don't do anything you feel might will make a good thing take a turn for the worse just getting out of the gate.
I hope all this rambling helped somewhat.
Mr naughty.