Ruairi and Teresa didn't get on with William and Harriet because of personality differences. The first couple were laid back, easy going and tolerant. The second couple were the opposite. Both couples were practising Catholics, but Ruari's and Teresa's Catholicism was open hearted and tolerant, and put love first. Harriet's and William's was narrow minded, rigid and intolerant and gave priority to laws and rules. This was shown by their condemnation of Niamh for living with Brendan and becoming pregnant by him, before they were married. Maire and her siblings took after their parents in their type of Catholicism, as Niamh did after her uncle and aunt.