<prompt> Human: PF, My husbands parents and teenage sister will move in with us starting next month while their own house is being built. We live alone, no kids, no pets, no other tenants. Here are the details and stats:- 4 bedrooms, 4.5 bathrooms, 3 garages- Mortgage is 4560mo including tax and insurance no PMI - Utilities so far for 2 people around 300-450 depending on the season- Pool maintenance 100mo- Gardener 100mo - Internet 70moThese are the home expenses at this moment. I laid them out for my in-laws too and they said we should be the ones deciding or at least proposing how to split everything since its our house. We sleep in the Master, one bedroom is converted into office, 2 are empty. Parents will sleep in one and sister will sleep in the other. Im not concerned about groceries, we can figure that out later. However, I have no idea what to propose. Would it be OK to divide the mortgage and expenses 4060 since we are 2 and they are 3? Does this situation turn us into landlords? Do we need to declare something on our taxes or just collect the amount from the parents and pay our mortgage as usual? Thanks in advance!  <response>: The split should be the following: you keep paying amd charge them nothing. Enjoy the rest of your life. There will come a time when you may need to live in their home. 