Marriages should be totally happy and most of life's satisfactions should come from the partner. Men and women are very different emotionally. Opposites always attract. Marriage will cure loneliness. Partners must be totally honest and tell all.
Marriage requires total trust.
Good marriage partners agree on every issue and never fight. Incompatible couples can't have a successful marriage. Volatile marriages never last, quiet unions last. An affair means there are problems in the marriage. An affair will destroy a marriage.