Well, I am with a hot Russian hottie. Fortunatelly we had the same ideas about threesomes and orgies so we became Swingers. I think the SW style is a good way to start and both enjoy. Not sure if you would be comfortable to see him enjoying.
However, after a while, at least to me, it happened that I started enjoying more to see her fucking than me enjoying other girls. I'm in transition to be a cuckold, I think it is what turns me on. And in the other hand, I'm not the greatest lover either. I don't fuck her that often instead I enjoy looking her beauty and seeing how she enjoys other dicks.
I'm probably in the side of you boyfriend, come and take a look of my thread and let me see thour thoughts about a simmilar issue. In my case she doesn't know I am in this site so makes it little bit different. If you ever want to talk please reach me at vamateur2 at gmail from there we can exchange skypes.