Related to what others have said, once a hubby "allows" this to happen, he has to realize he gives up most of his rights to dictate to his wife what she can do. Alot of husbands think this way. That's not to say they shouldn't talk and be honest and respect one another, but the hubs has given up any control he had or wanted. That's hard for some guys. I have learned from here alot of guys actually prefer this.
In my own experience, once I decided I was going to do this (my hubs suggested and begged me for a while) he was shocked how quickly my feelings about it shifted. Early boundaries were quickly crossed - alot of weekends away, overnights and clubs, multiple partners and all that. Was I addicted? I had a hard time saying no. It was definitely new and exciting, so you could say I was addicted. I'm still addicted because if my husband said me or BBC, I would probably choose BBC. I think its works fine with both, so hopefully it never comes to that! Now I have become more balanced with BBCs family, marriage, motherhood, all that stuff.