Civil Partnership and Certain Rights and Obligations of Cohabitants Act 2010
http://www.irishstatutebook.ie/2010/...0001.html#sec1
UNMARRIED cohabiting couples may apply for maintenance, property, pension or inheritance rights if the relationship ends, under the above civil partnership laws.
Live with someone, even part time, for 2 years with children, or 5 years without children and you are effectively deemed married by the state.