So, do you think its actually wrong for me to take part in their wedding? They clearly are not open to children; can I say they will absolutely, never ever have children? No, but they are definitely planning on not having any.
That is a sad state of affairs.
If it were me, I would either sit down with the groom to be, or if he is not in the immediate area, have phone conversation and say what you have to say. and I would say it very carefully so that he understands that you are not trying to stand in judgement of him, you are not trying to play the “holier than thou” card; what you are trying to do is follow your conscience in a matter that your Church has a position on, and that you are caught in a quandry.
And I would show up at the wedding (having already assured him that you will).
This may have an impact on your friendship, and may have one you don’t like. Or it may be a minor issue, or no issue at all.
People get their heads around an idea and make all sorts of plans. Some of them follow through; others grow some, and their plans change; either they outright reject their former plans, or they implicitly reject them. He and she might end up having kids. Or they might not. And given today’s general statistics of marriage, they may or may not stay married until death of one of them, kids or no kids; odds are not good in general.
That is just what I would do. If you still are questioning, make an appointment with a priest (don’t bring this up in confession - if for no other reason than you need sufficient time to discuss this and others may be waiting to actually go to confession - it is not the place for spiritual guidance or counseling). The shortest answer is that the best source for a question like this is not in a forum, but from a spiritual director.
