Answer
If a property is solely owned by one partner, the other partner doesn't automatically have a right to live in that property. In legal terms, for the non-owning partner their right to remain in the home is contingent upon the permission granted by the owning partner. Should the owning partner decide to stop allowing the partner to live there, they are only required to provide "reasonable notice" before the non-owning partner is deemed a trespasser upon expiration of this notice.
If you're living with someone who owns the home, you might still have the right to stay or claim a share of the property. These rights could be based on having a beneficial interest, if you've contributed financially to buying, paying the mortgage, or improving the property, you may have a right to stay and even claim a portion of its value.
If you have a written agreement or a verbal promise that you can live there, it could give you some rights. On the other hand, if the owner led you to believe you could stay, and you relied on that, you might have the right to continue living there.
But proving these rights can be tricky. Courts will look at the specific details of your situation, like how much money you put into the property and what agreements were made. It's not a simple process, and outcomes can vary a lot from case to case.