I travel with my wife a lot together. Once I tried a week long tip with one of my friends with whom I had never cycled together before and that was quite an experience. We had different expectations, different cycling experience and comfort-speed and at times it became miserable for both him and me. Yet most of the time it was all good. We met a couple of friends - around the world travelers on that trip (actually one of them) who said that they constantly "break up" for 2-3 days to cycle solo, later meet up again just to keep the relationship good. It all boils down to communicating needs, expectations, goals beforehand and on the fly though.