You can make a cohabitation agreement at any time, whether you are
about to start living together or if you have been doing so for many
years. Your family lawyer can help you negotiate this agreement and
can write it down in a way that it is likely to be respected by the
court in case there is ever a dispute about it.
You may also seek the assistance of a mediator to help the two of you
talk about the potential terms of a cohabitation agreement, or work
out what should happen using collaborative law.