Will I Have to Pay This Debt of Water

My question involves landlord-tenant law in the State of: Puerto Rico

I've been living on my brother-in-law's property for two years rent free. Living there the only thing I paid for was the electricity (which was under my name) and the water (which was under his sisters’ name). In the last year of me living there I realized that he had no title, no ownership, and no papers whatsoever of the property. Realizing this I stopped paying for the water and only continued paying for my electricity as I looked for a new place.

I am currently at my new place with a different problem. His sister is taking me to court for the debt I left her of $1,600 in water. Will I have to pay her this money? There was never any contract signed, no agreement made, and they had me on the property illegally without letting me know.

I know I've been naive but please, letting me know any information as to whether or not I have to pay off that debt would be helpful.

You ran up a $1,600 water bill while living in the place, rent-free? Whatever the situation may be with title, that makes it sound like you were taking advantage. Was the place in his sister's name? If not, who is the owner?