My sis husband mad cause my stepdad isn't paying rent this month. But when they all moved in this…

My sis husband mad cause my stepdad isn't paying rent this month. But when they all moved in this place the agreement was the 3 guys (my brother, my stepdad and my sis husband) would split everything 3 ways. Including the rent, lights, and water bills. So that's 285 rent a piece, 140 on lights a piece, and 25 a piece on water.... My sis husband only helped with his part of the lights once over the whole year and there after it's only been his rent share he's paid. So only my brother and stepdad been splitting the lights and water the whole time. So my stepdad wanting his money back for my sis husband part of the lights and stuff since they about to move out the end of the month. Which is understandable. But he got pissed and went to his room lol..i mean it's not right for you to run up the lights and water and not help pay your share... My sis pissed too. But it's only right that your husband pays his share of the lights since he hasn't the whole year...