Am I responsible for this cable/internet bill?

So I moved into this house for the summer for two months and was put onto the lease. Its a four person house and one kid was staying the summer and the other two moved out and one of them subleased their room to another kid. I moved all of my things into the house but didn't have a bed which wasn't a problem because my girlfriend lived down the street and I had a lot of vacations planned. So I pretty much used my room as a storage locker and went there maybe once a week but was never there for more then an hour or spent the night. I put the gas in my name and paid that bill split between us three and the rent was split 4 ways so the kid who moved out but didn't sublease, still had to pay. Now I'm getting texts from one of the kids who moved out but was responsible for paying the cable/internet bill asking for $70 for two months of cable split three ways. I told him that I didn't use these services so why should I pay? Now he is threatening legal action if I don't pay for these services