no disrespect to you sister, but if your husband wants such excess in sexual matters why is he married in the first place?
it's better if you solve this as quickly as possible sister, human nature at it's base does not discriminate and only seeks to fulfill it's desires, and you're better off without having to make such choices in the first place.
I'm not saying you have to divorce him right away, but your husband is going down a dangerous path if he hasn't already, and that path after the perversion has passed leaves little more than pain and heartache, unless you wish to see him being intimate with another woman like he's only allowed to be with you, I suggest you see a marriage counselor first, together, and if that don't work out see a lawyer, you said you're in the US, so there is no lack of marriage counselors.
also, I know that you're having a hard time with this, but you have to realize that part of the blame falls on you, either he's taken a fantasy overboard-all people have them, regardless of the exact details, but they are just that, fantasies, or you're not enough for him in bed, if it's the latter you need to do something, that is not an area I'm an expert in, nor should it be discussed publicly, but you're a grown up and married, and that marriage hinges on no small part in you both being sexually satisfied, hence seek out help in this as well. ask your sister or dearest friend or whomever you trust, or more easily walk to the nearest bookstore and grab a copy of the myriad books that deal with this. either way, there's endless ways to add a spark to intimate relations without involving a third party.
take this matter seriously and proactively, never feel helpless, and God willing you will be in a better situation.
if it is indeed a fantasy gone too far, then he needs to take concrete steps to curb it, we only believe what we want, no one actually needs to act upon a fetish, rather constant reinforcement is the main culprit, and this particular matter he asked you about is not widely talked in normal settings, there's either the internet-porn, chat rooms etc- or the people he would see in the bar, for the sake of both of you as individuals and as a couple he needs to stop, you need to communicate this to him as best as you can, make it no small matter, by not reacting enough to his going to the bars and talking about such things you're only giving an image of resignation and even acceptance.
and finally may God be with you and make your matters better, & I apologize if this was inappropriate in any way.
