It might seem boring to some, but spending time reading together can bring a couple closer. Each of them might have their favourite authors, and they can learn a lot just by seeing what their partner is interested in reading. Some of them might be looking for a good non-fiction book full of facts, and the other could get lost in a fantastic world somewhere out in space. Each person will reveal facets of their own personality, so spending an afternoon at the library could be a good way to get to know each other better.
Some people love to read, and they often like to share their favourite books. Couples doing this can find a wealth of insight into what drives their partner. If one of them is interested in books about true crime, it might show they like a good mystery. Books that teach people how to do things indicate learning is a priority, and some of the subjects could lead the couple to future projects.
Each book in the library has its own merit, and sharing the thoughts and ideas in favourites can help a couple look at where they are headed together. If one of them is interested in building a house, they might check out books on plumbing and electricity. While they might not be quite ready to start building, at least their partner will know they have a handle on how things get done.
Books that take people away from the world can also reveal bits and pieces of their personality. A good novel can make people take a look at the world around them, and it could spur them on to make positive changes. Another person might choose the same novel, but their goal would be to escape a world they find imperfect. Each of these concepts might tell their partner whether or not a future together is possible.