Domestic partners live together, but are not married, and have not participated in a civil union. However, in some states – California, Washington, Oregon and Nevada – this kind of a partnership is almost the same thing as marriage, or the same as legally sanctioned different sex-unions and same-sex unions. Domestic partnership is the current lingo used to describe these unions. The rights and responsibilities involved in situations like this are also still being defined in many jurisdictions.
Some people refer to the breakup of a domestic partner agreement as palimony, largely because the parties in the union are not married, but are more like pals living together and pooling their resources.
In some areas of the U.S., domestic partners who have lived together for a long period of time, but have not married, may get legal protection with a domestic partnership. Some of the issues typically covered in these agreements may relate to support issues in the event of a breakup, property ownership, and custody of children; not all that different from the kinds of issues that may arise in a marital breakup.