If you live or “cohabit” with someone (regardless of whether they are the same gender as you or the opposite gender) and you are not married, then people often say that you are in a common law relationship. There is no precise definition of what constitutes a common law spouse. In Ontario you need to live together for three years or live together for less but be the parents a child. Under most federal laws, you are considered a common law couple if you have been living together for one year or longer.
Perhaps the most important distinction between married and common law spouses is the right to property when the relationship breaks down and the parties separate. Couples who live together do not have the same rights as married couples to a share in the value of property, including the home they live in, unless the property is in both of their names.More