I tried this last night - it's all a bit of guess work to me, and that was just with one! But basically it says where the big kicks are, they're feet. Where the little wiggly feelings are, they're hands. Then you should feel a firm area of the back, and a bulge for the bum. In your case, it wouldn't be too hard to work out at least where the feet are of each one would it? You'd be feeling the big kicks in two places right? Other than that, I don't know how easy it'd be to tell which parts are Twin A & which parts are Twin B