Im not married – yet; send prayer – so take this with a grain of salt. But viewing natural family planning as a up-up-down-down-left-right-left-right-b-a-start Contra 30 lives work-around to marital sex is wrong. Also, there is nothing wrong with NFP properly understood.
*This post inspired by sedevacantist controversialists I chat with.
Wood Faileth 
My fiance and I are going through pre-cana right now and talking a lot about starting a family, as naturally happens. The way our priest described it is that NFP has context. Newly weds planning to avoid children should probably not get married–children is one of the big reasons to get married, and sex is merely required to produce those children. Couples marrying for the sex and not the family puts gratification first, and that is what constitutes the sin. Self gratification over making God happy. It’s the root of why a lot of things are sins.
Praying for you, my friend!
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there was a second part to this that I accidentally left out. Newly weds planning to avoid children should not get married. Oldly-weds that already have some number of kids could deploy NFP to manage their family, once that family has already been established. Same practice, different context, different moral calculus.
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