Paying in laws phone bills

Hello I’m just trying to see if I’m wrong would you still be paying your father in laws phone bill when you’re expecting a child and my MIL & FIL are still married and live in the same household however he’s sick and unable to work… his bill $60 a month and refuses to pay for it or his wife and I’ve talked to my husband plenty of times and he refuse to have a conversation with his father & mom about the phone bill.. I feel like I’m being petty but it’s been times we needed that $60 and that can go towards our baby pampers and formula especially we plan on buying a house in a year or two I’m trying to limit bills and I also won’t be working after the baby comes due to nursing school but I don’t understand why his wife can’t atleast pay his bill and it’s annoying me so much