While my wife and I both read the Bible, we almost never bothered to make sure we were reading the same passages, as we were generally thinking about things in completely different ways anyway, and weren't able to learn from each other when it came to that. If we would have done so, I would think I would have suggested the Gospels and Old Testament wisdom literature.
Also, augustin, sex takes about 4 minutes... you don't have time for Bible reading after that?

Wow, perfect for in between doing the dishes and paying bills! Please PM me your tips. Kidding.
We don't really read the Bible together (We differ so much on what we feel like reading at the time that we just read separately...should probably change that :-/ ), but I think that looking at the daily suggested Bible readings is a good idea.
Is there such thing as an Orthodox devotional? I haven't looked. But we used to do devotionals while we were dating -- so there was a little commentary after the Bible verse or chapter.
Also, starting with the New Testament and going through it would be good, since you can talk about applying the principles in your own marriage as well as your personal lives. I think the Gospels and the Epistles would be my top picks as to what to read together. But I'm biased because of my own personal preferences.