Then I guess if they decide to kick you out, you will have to rent, or offer to pay them rent. Your BF should ask/tell his family to let you live there, until your demise.
I am lucky in that respect, my wife has told her kids in no uncertain terms, to let me continue living in 'our' house, and even have a new lady to 'take care of me', her kids have their own house and lives to live, they are both hard workers. But I honestly don't think I could live in the same house anymore, remembering her joy when the durian trees fruit, and especially walk around 'our' village with a new lady in tow. I would be the same off financially having to pay rent as living with my wife in a house 'She owns'. But one never knows until the worse happens.