After analysis, there are the following possibilities:
First of all, you subconsciously have the psychology of resisting living with your in-laws, fearing that you are not welcome or indifferent on the surface;
Second, or your father-in-law is more casual in his daily life, which makes you psychologically stressed;
Third, your father-in-law is very strong. This dream indirectly implies that he is overbearing in your mind and even tends to control you (just like a carnivore divides the boundaries in the form of urinating);
Fourth, this possibility is relatively small, and you have wild desires for your father-in-law.
Pure psychological analysis is scientific and does not involve superstition. Please forgive me if I am wrong!