Couples get in a rut.  They do the same routine daily and weekly.  You need new experiences to keep the chemistry or passion of the relationship strong.  Studies have shown that new novel experiences can stimulate the production of the neurochemicals dopamine and norepinephrine, which show up in the brain in the early, blissful stages of a relationship.  What this means is that you need to keep the relationship new and growing. Look for new things to do together and enjoy as you explore life together.