This paper sets out to uncover some of the less prominent factors that generate antipathy toward marriage between Catholic and Protestant in Northern Ireland. Attitudes and responses to these mixed religion unions are described in the context of Northern Ireland’s wider pattern of sectarian social relations. The paper suggests that particular cultural ideas about the relative influence of men and women underlie the more obvious conflict in Northern Ireland over religious and political identities which intermarriage represents. The paper concludes with some modest reflections on the ‘slippage’ between apparently private acts of individual ‘tolerance’ and wider patterns of public ‘prejudice!’.