Let's say you are married and both work full-time jobs. Your spouse pays a few hundred a month out of her own paycheck to help pay her retired mother's rent. A few years later, you have children and your spouse wants to quit her job to stay home with the kids.
Assuming you had excess income, would you offer to chip in for your mother-in-law's rent?
In a marriage or long-term, committed relationship, do you have the "what's mine is ours" mindset?