Every relationship has times of abstinence.  Couples using NFP have regular and expected times of abstinence (about  7-10 days in an average cycle), which they accept as part of their shared responsibility for their combined fertility.  While abstaining can be challenging, it can also bring couples closer as they develop ways of sharing their love at other levels--spiritual, intellectual, emotional, conversational.  Some NFP couples even say that the waiting leads to a small honeymoon every cycle!