Dear Mary: how can I improve a friend’s appalling table manners?

Q. I recently attended a wedding which was (for me) quite ‘grand’, with a church ceremony followed by a reception. I cleared my diary for the weekend. The wedding, in Exeter, was organised by wedding planners who inundated me with pieces of paper and emails about the logistics, but on arriving at the church and speaking to some friends it became apparent that there was a separate evening party to which I had not been invited. The groom is not a close friend, and I was delighted to have been invited just to the wedding and reception, but I was in the difficult position of deflecting the question in order not to seem ungracious. Looking again at the invitation and accompanying materials, there is no hint to be found anywhere that the reception did not last into the evening. Surely no one would want to create this kind of ambiguity, not only for those like me who were partially invited, but also for those with full invitations who assumed everyone was invited to both parts of the wedding.