Maybe he doesn't know any other topic to talk about? Perhaps you could try talking about the things you did together, so you know what to talk about.
I know it's difficult to find something to talk about sometimes!
I do think it's better to have a fiance or husband, who doesn't want to be called too often or wants to be together every second, it wouldn't leave you any time to do something else you'd like to do or even breathe, really, it's irritating if he's keep calling you and even keep demanding that you should call him! I once even had a female friend who did that to me, and that was annoying too, but when your fiance or husband does that, it's even more annoying!
Or are you the type of person who wants to be together every second with your partner, as if you're glued to your partner? That would be scary!