This all comes down to understanding that your mate's spirit and heart are the most important but secondarily understanding that each has some level of responsibility to make an effort to not let yourself go, as physical attraction clearly plays a role in marriages. This will differ among relationships, so it is imperative that a couple communicates as selflessly as possible but with clarity as to how they feel about this issue. Remember, we all fade a bit with time so fall in love with your mate's spirit, which is everything but the physical.