If your husband is making jokes about him being your boyfriend he might ok with the idea.
My partner (Gamerboy) made similar comments about our friend (MadScientist). One night last year Gamerboy and I were very drunk and I finally gathered the courage to explain about polyamory and my feelings. He was more than ok with it, turned out he's poly too. In fact he was the one who pointed out I had feelings for MadScientist that I had previously been oblivious to.
There are a lot of wonderful resources here and elsewhere to check out and good luck with everything.