If you asked the average Catholic to list 10 tips to build a better marriage, chances are Natural Family Planning (NFP) would not make the cut. Most Catholics, if they think of NFP at all, think only of those three troubling words, "Not tonight, dear." But more than a means of regulating birth, NFP is first a means of building communication, affection, respect and a sense of joyful freedom in a couple's sexual relationship. As...