Above is a copy of the church posterwhich has caused something of a stir in NZ.

In this article Mary and Joseph post-sex poster upsets Catholics objections to it are raised by a Catholic spokesman.
I couldn't help but be struck by how they - for my mind - have grasped the wrong end of the stick when it comes to what is "offensive" about the poster. The offense mentioned by the spokesman is that the poster does not support the Catholic church's tradition that Mary remains a virgin.
Now - this has never been a teaching of the protestant church - which turns to the Scriptures rather than tradition for its ultimate authority - and finds there the teaching that Mary and Joseph had a sexual (that is normal) marriage relationship after the birth of Jesus (Matthew 1:25) and that this produced siblings for Jesus (Mark 6:3).
What is offensive/blasphemous about the poster - is that it implies that God and Mary had sex! Such a suggestion does undermine the doctrine of the virgin birth (which both Catholics and Protestants hold to) and also supports the mistaken view that some other religions have of ours - that Christianity teaches that God and Mary had a sexual union.