Any couple will tell you that many situations come up which do not allow them to engage in intercourse when they feel like it.  Illness, travel, houseguests, and numerous other situations are simply aspects of normal life which temporarily rule out intercourse.  Likewise, if the intention is to avoid a pregnancy, it becomes just as logical to abstain from intercourse during the time of fertility.  Although abstinence from intercourse is not always easy, in no way is the use of NFP harmful to a marriage.  Many couples report that periodic abstinence enhances their relationship through non-genital sexual communication.  To abstain from intercourse out of respect for each other and the existing family becomes itself an act of love.  The mutual anticipaiton to resume intercourse after a time of abstinence frequently intensifies the physical dimension of their sexuality.  Intercourse free of chemicals, devices, and fear becomes most spontaneous.