A lot of it never does make any sense. After reading your post, to say he's confused, is quite clear, but he's obviously not confused about one thing. The great sex part your cousin is talking about, well, sometimes there's great sex with world-class cheaters, and the cheating brings it on. Not to say that's what's happening in your case at all, but I'd say there appears to be an emotional affair at the least, and that's where he's at right now.
Have you tried DB'ing techniques yet? Look over some of Michele's articles, and get one of her books. This sounds like a new thing that's happening to you and it may well be worth your effort to do the "right" things now to refocus your H (husband) on your relationship.
You can go dark for one: no more sex--minimal contact, only for important reasons--get him wondering what's going on with you. Right now he seems to be enjoying having his cake and. . . .