I prefer Landlady over roommate, but also prefer the MC to be older than "just got back from Uni." or "Male Landlord took MC away from Landlady and now young MC is back" Age.
As a family man, we must take care of everyone. Ensure all their needs are met.
We can't let a clown exploit your insecurities and existential emptiness. They can never give you the true love that a son and a brother can give. It's not a matter of preference, but of responsibility to ensure your complete happiness.
A good son visits his mother regularly and ensures she is filled with love. She may be so happy that you might gain a new little sister.