you can purchase the house jointly with your husband and father in law
2) when two or more people buy a property but do not specifically mention the share that each has in the property, a 'tenancy-in-common' is created. All the coowners can use the entire property and every co-owner is deemed to be having an equal share in it. After the death of one of the co-owners, the interest in the house does not pass on to the other co-owners but to the legal heir or a person named in the Will of the deceased, who will then become a 'tenantin-common' with the surviving co-owners.