Ok so my husband has had a fantasy of watching me have sex with another guy for years now. A long time ago we did have a threesome with a mutual friend, I felt guilty after the incident, and after that we didn't do it again. Well this past year life had got in the way and we had a boring sex life and I remembered how happy and exciting things were after that one night so I decided if he brought up the subject again I would bite. Well he brought it up and I said I would be open to talking about it and possibly trying it. Needless to say he was excited. So I started reading more about it and I discovered that there were names for this fantasy/fetish called Cuckold and hotwife. We started off going to a swinger party and then joining a website. I warmed up to the idea for a few reasons #1 it sounded hot, two men all over me, #2my husband seemed to be so in love with me. Well I found a guy that seemed "my type" we met a few times, then it "happened". Well the guy seemed perfect, he was good looking, fun, charming but the sexual part I hated, he was really rough I mean not in a hurtful way just very "fast" and not romantic at all. I know that seems weird but I am a lady and regardless of the situation I still wanted that passion. Well after that my husband was obsessed! He fell in love with this new lifestyle but I didn't. It consumed our daily life our sex life and we went to a few more parties and I just couldn't get into it. Actually the last party I ended up crying in a corner because I felt bad that I couldn't do this for my husband. He felt bad and we left and he apologized for upsetting me just for his own pleasure. He says he will not bother me about it again but I know how happy this makes him. Well things were good for us sexually for a while but the last week or so he has been hinting little things like for example tonight he text me from work and said I want to talk dirty to you but I'm trying to be good. So I say well talk dirty to me then and he says I can't because I don't want to upset you I'm trying to change. So I say is that the only dirty way to talk to me. He said it the only thing that comes to mind. So I said ok so beside the "me sleeping with another man" fantasy what else do you get excited about and he says I'm not sure what is there to be excited about after 15 years!!!!wtf?? I'm so scared this is going to ruin us. He says he will not bring it up again but for me it's like wow nothing except for that fantasy excites him!!! Is he ever gonna be truly happy with me??
As a man who is getting married in a couple of months, I feel touched by your situation. For our part, we do share fantasies of incorporating another male into our sex life, but this is only pure fantasy (to spice up the act). I can't imagine a situation where I would let another man have his way with my wife because I did lots of research on the topic. It turns out that many women fall in love with the other man because he ends up being better sexually and they usually have secret sex following the first act, outside of the husband's knowledge. There is a distinction to make between a threesome with another man (MFM) or cuckolding (where a married husband enjoys seeing his wife have sex with other men). I believe your husband falls in the latter category and this form of lifestyle cannot be undertaken without a high level of trust between the couple, a mutual agreement between the couple, and respect of the wife's wishes. As you can see, I've done my homework.
I believe you need to see a couples' therapist because your husband clearly has an obsession and this may be due to some other psychological reason. Also, choosing a particular lifestyle has to be mutual, and if your husband is coercive on you having intercourse with other men then it's hot healthy and is not a sign of love, but personal satisfaction. My words may sound harsh, but your husband needs a therapist to find out where this obsession originates.
Lastly, I hope your marriage survives because I believe you both love each other and this obsession, from your husband, is just a 'kink' (no pun intended) on your marriage that has a solution.
If you have any questions, please feel free to contact me. I have lots of research under my belt (again no pun intended) which I believe could explain some of your husband's novel fantasies.